SKKU Spring, 2014
Honor Calculus 1
(고급미분적분학1)
담당교수 Prof : LEE, Sang-Gu
http://matrix.skku.ac.kr/Cal-Book/
http://matrix.skku.ac.kr/Calculus-Story/index.htm
http://matrix.skku.ac.kr/Cal-Book1/Ch1/
http://matrix.skku.ac.kr/Cal-Book1/Ch2/
...
http://matrix.skku.ac.kr/Cal-Book1/Ch15/
Final PBL Report (종합- 강좌의 기록)
Name(학생의 이름) : ***
Major(전공) : ***
SN (학번) : *** etc
e-mail (이-메일): ***
< 강의, 녹화, 학생 문제풀이, 녹화, QnA 1140건, 공지사항 80건, 참고자료, 읽을거리 등 >
[개인성찰노트] 자기평가, 동료평가, PBL에 대한 학생 반응!
1. 이번 학습과정에서 배운 내용은 무엇입니까?
이번 학습에서는 중간고사 범위에 비해 새로운 내용들이 많이 있었습니다. 크게 적분, 수열, 매개변수 방정식, 극좌표로 나눌 수 있습니다. 수열의 경우 수렴판정법에 대해 자세히 배웠고 taylor, maclaurin, binomial 수열에 대해 새로 배웠습니다. 극좌표도 고등학교 때에는 하지 않은 내용으로 데카르트 좌표계를 벗어난 새로운 좌표계를 배웠습니다.
2. 학습과정에서 어떤 방법을 통해 학습했는지 구체적으로 적어주세요.
이번 학습과정에서도 중간 때와 마찬가지로 sage tool을 이용하였고 qna에 문제를 올리고 수정받는 방식으로 학습했습니다. 이번에는 특히 sage grapher를 이용하여 매개변수 방정식의 변화를 애니메이션 형태로 볼 수 있었습니다.
3. 이번 학습과정에서 내용이나 방법면에서 인상 깊었던 점은 무엇입니까?
위에서 말한 바와 같이 sage grapher를 처음 사용해본 것이 인상 깊었습니다. 단순히 그림을 그리는 것에서 끝나는 것이 아니라 변화과정까지 시각적으로 볼 수 있어 직관적인 이해가 되었습니다.
4. 이번 학습과정에서 다른 과목의 수강이나, 학교 공부 외, 취업 후 등에 적용할 만 점은?
이번 학습과정에서 배운 내용 중 특히 수열 부분에서 모든 함수를 다항함수로 바꿀 수 있게 되어서 아무리 복잡한 식이 나오더라도 계산기로 계산할 수 있게 되었는데 나중에 만약 취직을 하게 되면 쓰게 되지 않을까 싶습니다.
* 기말고사 서술형 문제 예 : 문제 풀어 올리고 질문과 답을 하면서 공부한 학생은 별도로 시험공부를 할 필요가 없을 것입니다.
< 기말고사 서술형 문제 예 >
http://matrix.skku.ac.kr/Calculus-Story/index.htm 에서 발췌 예정
우리는 생활하면서 ‘주어진 곡선의 일부분의 길이나 그 곡선 위의 어떤 점에서의 접선은 어떻게 구하나?’ 또 ‘주어진 곡면의 일부분 표면적은 어떻게 구하나?’와 같은 질문에 접하게 된다. 일반적으로 표현하면, 시간에 따라 두 변량(Variable quantity)이 변하는 비율은 어떻게 계산할 것인가? 하는 문제와 만나게 되는 것이다. 이 모든 것들을 계산할 수 있게 하는 방법이 수많은 과학자들을 거쳐 뉴우톤과 라이프니츠에 의하여 체계적인 방법으로 정리되어 소개되었으며2), 이와 관련된 다양한 연구들은 인류 역사 발전에 절대적인 영향을 끼쳤다. 그 발전 과정을 보면 ...
1. 라이프니츠가 생각한 <미분의 개념> 은 무엇인가?
2. Archimedes를 비롯한 수학자들은 원의 경우에 적용한 유사한 방법을 확장하여 타원형이나 더 불규칙한 도형의 면적에 적용하였다. 이 방법의 아이디어는 무엇인가?
3. 미분을 배우는 이유는 무엇일까?
4. 컴퓨터 단층 촬영 장치인 CT에는 적분의 어떤 아이디어가 이용된 것인가?
5. 19세기에 Bernard Bolzano, Augustin-Louis Cauchy, Karl Weierstrass 등을 거치면서, 극한을 엄밀한 논리(argument)를 이용하여 완전한 형식화 방법은 무엇인가?
6. 미분과 적분을 이어주는 정리는 무엇인지 말하고, 그 이유에 대하여 아는 대로 서술하시오~~
7. 행성들의 운동을 나타내는 Kepler의 법칙을 설명하기 위하여 미적분학을 개발한 사람은 누구인가?
8. 근사와 Taylor급수가 왜 중요한지 아는 대로 서술해 보시오.
9. differential dx 는 어떤 식으로 이용되나?
10. *** 을 구하기 위하여 거치는 과정을 단계별로 서술하시오.
등 등 우리가 배운 내용에서 기말고사에 출제할 수 있는 문제를 생각 중이랍니다.
QnA 에 위의 질문에 대한 답을 하면서, 연습을 해 두기를 권한답니다.
(여러분의 활동 중 같이 공유할 좋은 질문과 답이 시험 문제가 될 가능성이 가장 높을 것입니다.)
따라서 질문과 답을 하면서 공부한 학생은 별도로 시험공부를 할 필요가 없을 것입니다.
행운을 빌어요!
Good luck on your (서술형, Story telling) Midterm Exam and PBL~
담당교수 드림 From your Prof.
◆ Your QnA Records
제목: 0의0승은 어떻게 처리해야하나요?
그래프 그려보니 그냥 1로 취급하는 것 같던데 그런 식으로 봐도 되는 건가요?
제목: dir='minus'은 무슨 의미인가요?
dir='minus' 어떤 명령어죠? 그리고 x^x에서 음수에서는 그래프가 그려지면 안되는 거 아닌가요?
제목: Smart learning environment
smart learning 영상을 보기 전에 솔직히 책이 사라진 교실이란 상당히 집중이 안되있을 거란 생각이 많이 들었다 . 하지만 영상속의 모습은 자발적이었으며 집중도가 높았다. 특히 실험실에서 이제 책이라는 것이 주어진 지식을 얻는 것이 아닌 자신만의 새로운 책을 만들어가는 과정을 보고 깊게 감명 받았다.
스마트러닝은 한 과목에 국한되어있지 않고 실험, 체육, 음악 외 다양한 분야에서 활용될 수 있는 새로운 교육의 패러다임을 제시하고 있다.
http://www.youtube.com/watch?v=Ll1P_57qluo
제목: Calculus-History-p
발견이란 것이 항상 관측을 바탕으로 하지만, 관측을 한다고만 해서 발견이 이뤄지지않는다는 것을 케플러의 사례를 통해 알게되었습니다. Tycho Brahe는 평생을 육안으로 천문관측을 한 사람으로, 육안으로 볼 수 있는 극한까지 이른 최고의 관측 천문학자였지만, 그의 데이터를 바탕으로 일정한 법칙을 알아낸 사람은 결국 Kepler였습니다. Tyco Brahe 역시 같은 데이터를 가지고 있었지만 발견하지 못했고 Kepler는 그 데이터를 분석함으로서 발견을 이뤄냈습니다. 이와같은 일화를 통해서 수학에서의 분석의 중요함을 느꼈습니다.
제목: 미적분학을 배우는 이유에 대한 생각
미적분학에 핵심은 변화에 대한 관찰 그리고 그것을 통한 어느 시점에서의 상황의 예측정도라고 생각합니다. 미적분학에 대한 일상생활관련 문제를 보더라도 대포를 쏘아올린 것이 포물선을 그려 얼마정도 후에 어느 위치에 있을 거라던지, 물을 붓는데 이것의 높이변화와 부피변화를 구하라던지와 같은 문제들입니다. 이러한 일상생활관련 문제들이 단지 문제를 위한 문제는 아닐거라고 생각합니다. 그리고 또한 위 같은 문제들이 묻는것은 대체로 미래의 어느 때입니다. 따라서 위 같은 사실을 종합적으로 고려해볼때 우리가 미적분학을 배우는 이유는 현실을 관찰하고, 그 관찰한 것을 이용해서 '미래를 예측하기 위함' 이라고 생각합니다.
제목: sage에서 dir의 의미: limit(f(x), x=a, dir='plus') f(x)의 x=a+ 에서의 극한값
이번에 세이지를 통해서 극한값을 구하는 중에 명령어 dir의 의미와 극한값을 구하는 법을 알게 되었습니다.
limit(f(x), x=a) f(x)의 x=a 에서의 극한값
limit(f(x), x=a, dir='plus') f(x)의 x=a+ 에서의 극한값
limit(f(x), x=a, dir='minus') f(x)의 x=a- 에서의 극한값
'dir'=direction 방향을 나타내는데 쓰입니다.
http://matrix.skku.ac.kr/sage 에서 lim을 검색하면 극한계산에 대해서 나옵니다.
제목 : Arc length 구하는 아이디어
곡선의 길이를 구하는 것은 그 곡선을 미세하게 분해해서 보는 것으로 시작한다. 이때 곡선을 매우 작게 쪼게면 직선과 같다. 이때 그 직선을 직각삼각형의 빗변으로 생각하면, x의 미소변화량과 y의 미소변화량이 각각 밑변과 높이가 되고, 따라서 피타고라스의 정리를 이용하여 구할 수 있다((x^2+y^2)^1/2).
제목 : Center of mass를 배우는 이유 - 내용요약
질량중심을 배우는 이유는 질량중심이라는 것이 특정한 상황에서 구하기 쉬울 수 있고, 그 질량중심을 안다면 계산이 쉬워지기 때문이다.
In physics, the center of mass in space is the unique point where the weighted relative position of the distributed mass sums to zero.
Calculations in mechanics are simplified when formulated with respect to the center of mass.
In the case of a single rigid body, the center of mass is fixed in relation to the body, and if the body has uniform density, it will be located at the centroid.
The center of mass may be located outside the physical body.
The center of mass is the mean location of all the mass in a system.
( 질량중심을 잡음으로써 계산이 간단해진다. 하나의 강체(간단히 변형이 일어나지않는 물체)에서 질량중심은 고정적이고 질량의 밀도가 같다면 질량중심은 중심점에 위치하게된다. 질량점은 물체밖에 있을수도 있고, 시스템에서 모든 질량의 실질적 위치가 된다.)
2. SKKU Calculus - Record (기록)
[동영상 강의]
1.1 History of Calculus http://youtu.be/ODfMaHgIhAc
How to manage our class Review http://youtu.be/XWEQFlv4jKc
미적분학의 개념 http://matrix.skku.ac.kr/Calculus-Story/index.htm
Chapter 1. Functions
http://youtu.be/cl8GqIWIRD0
문제풀이 by 곽주현 http://youtu.be/BNKUzSohiD8
문제풀이 by 장찬영 http://youtu.be/x0E0ZMxZ3Og
문제풀이 by 임효정 http://youtu.be/vx7GCWY68Zw
Chapter 2. Limits and Continuity
2.1 Limits of functions http://youtu.be/VBCeAllP1M0
문제풀이 by 장재철-이훈정, http://youtu.be/LZSmRPAAXME
문제풀이 by 황인철 http://youtu.be/hj8d-j_DGf4
2.2 Continuity http://youtu.be/zGxx3PUCTnM
문제풀이 by 이훈정 http://youtu.be/azrkT1RP4-c
Chapter 3. Theory of Differentiation
3.1 Definition of Derivatives, Differentiation http://youtu.be/A-vDsF9ulTs
문제풀이 by 김태현 http://youtu.be/7wTBWuk2CzU
3.2 Derivatives of Polynomials, Exponential Functions, Trigonometric Functions, The product rule http://youtu.be/XXMnCESesfQ
문제풀이 by 조건우 http://youtu.be/Ei5KGW9vZhE
3.3 The Chain Rule and Inverse Functions http://youtu.be/HfScHEsPfKI
문제풀이 by 유휘의 http://youtu.be/aSKm12922FE
3.4 Approximation and Related Rates http://youtu.be/ViRwEJ0Wfkw
문제풀이 by 김종민 http://youtu.be/JmBOv6_D6qA
Chapter 4. Applications of Differentiation
4.1 Extreme values of a function http://youtu.be/mXVU8OqIHJY
문제풀이 by 김태영 http://youtu.be/_V4MryNEzWY
4.2 The Shape of a Graph http://youtu.be/cZrAF_77On4
문제풀이 by 김태영 http://youtu.be/SVOWADHlzV8
4.3 The Limit of Indeterminate Forms and L’Hospital’s Rule
문제풀이 by 신종희 http://youtu.be/gR2luDDPsMY
4.4 Optimization Problems http://youtu.be/k0NtkmZFnh8
문제풀이 by 이승철 http://youtu.be/AELEV2ElaeQ
4.5 Newton’s Method http://youtu.be/VxCfl2JzMYU
문제풀이 by 이승철 http://youtu.be/fdBHQ46g9RE
Chapter 5. Integrals
5.1 Areas and Distances http://youtu.be/mT_oxlD6RSA
문제풀이 by 남택현 http://youtu.be/Y_nCn76RPmY
5.2 The Definite Integral http://youtu.be/GIm3Oz58Ti8
문제풀이 by 남택현 http://youtu.be/iUsf1h_hTAE
5.3 The Fundamental Theorem of Calculus http://youtu.be/Zf1HT2H2fbA
문제풀이 by 정승찬 &Kim http://youtu.be/Pa4Z38KkDVY
5.4 Indefinite Integrals and the Net Change Theorem
5.5 The Substitution Rule http://youtu.be/h7tmvmNOliU
문제풀이 by 이한울 http://youtu.be/0TMbpCPO4Uc
5.6 The Logarithm Defined as an Integral http://youtu.be/kD0Z9PqetsA
문제풀이 by 이한울 http://youtu.be/ymDImdIQ90c
미적분학 with Sage Midterm Exam http://youtu.be/QAEI7A2DMMM
Chapter 6. Applications of Integration
6.1 Areas between Curves http://youtu.be/o53phm5cqJE
6.2 Volumes http://youtu.be/4-ChOAFbJAs
문제풀이 by 김종민 http://youtu.be/Fd4Mguf2dbU
6.3 Volumes by Cylindrical Shells http://youtu.be/qM1izf8qeX8
문제풀이 by 신영찬 http://youtu.be/gNaKkA0UNHg
6.4 Work http://youtu.be/u3ZaJWhKy6k
문제풀이 by 김건호 http://youtu.be/SmIo2yaxNsY
6.5 Average Value of a Function http://youtu.be/zmEeGmwQTB0
문제풀이 by 신종희 http://youtu.be/BVahd-DJoe8
Chapter 7. Techniques of Integration
7.1 Integration by Parts http://youtu.be/WX-6C9tCneE
문제풀이 by 이인행 http://youtu.be/jKCAGJ4HqvQ
7.2 Trigonometric Integrals http://youtu.be/sIR0zNGQbus
문제풀이 by 김태현 http://youtu.be/ytETYf1wLbs
7.3 Trigonometric Substitution http://youtu.be/avTqiEUi8u8
문제풀이 by 이훈정 http://youtu.be/utTQHIabTyI
7.4 Integration of Rational Functions by the Method of Partial Fractions
문제풀이 by 장재철 http://youtu.be/SkNW_bax0YI
7.5 Guidelines for Integration http://youtu.be/Fgn8U4We60o
문제풀이 by 김대환 http://youtu.be/-N9Fe_Arp2c
7.6 Integration Using Tables http://youtu.be/tn9jLkgTMp8
문제풀이 by 조건우 http://youtu.be/EnEQ9ZS3B_k
7.7 Approximate Integration http://youtu.be/hg2pw1n1cZI
7.8 Improper Integrals http://youtu.be/rquxbYrC0Yc
문제풀이 by 이송섭 http://youtu.be/C3kb4c9nLXM
문제풀이 by 이인행 http://youtu.be/dfSkjvmSXYo
Chapter 8. Further Applications of Integration
8.1 Arc Length http://youtu.be/7OVqI20z_Bw
문제풀이 by 남택현 http://youtu.be/A8N-mDD0ja8
8.2 Area of a Surface of Revolution http://youtu.be/Eq4i2A8eKxA
문제풀이 by 정승찬 http://youtu.be/yZFJDJgTJfw
8.3 Applications of Integral Calculus http://youtu.be/1ZAJeP16pAQ
8.4 Differential equations http://youtu.be/uHfOjz8I4-s
Chapter 9. Infinite Sequences and Infinite Series
9.1 Sequences and Series http://youtu.be/rz8ZS4Y_cvc
문제풀이 by 문지호 http://youtu.be/Qo0MArZG2EA
문제풀이 by 이원준 http://youtu.be/O6y1v5fJA0k
9.2 Tests for convergence of series with positive terms
문제풀이 by 김범윤 http://youtu.be/1flKAnlv9LA
9.3 Alternating Series and Absolute Convergence http://youtu.be/NtSitFNv9Mk
문제풀이 by 계성곤 http://youtu.be/e_5D0dzrqwc
9.4 Power Series http://youtu.be/426kkrMArgs
문제풀이 by 배성준 http://youtu.be/R3AcB12z2kk
9.5 Taylor, Maclaurin, and Binomial Series http://youtu.be/3zSPSvYHJQI
문제풀이 by 우시명 http://youtu.be/NSFrYRYZ6Qc
Chapter 10. Parametric Equations and Polar Coordinates
10.1 Parametric Equations http://youtu.be/hQGCZk1tpuA
문제풀이 by 문지호 http://youtu.be/uz1DkKVeD2k
문제풀이 by 임효정 http://youtu.be/Ybs68e0iMZI
10.2 Calculus with Parametric Curves http://youtu.be/QFMSbGKhoX4
문제풀이 by 장찬영 http://youtu.be/yF5oZOQVnCE
10.3 Polar Coordinates http://youtu.be/lKPJeAGw0ZA
문제풀이 by 계성곤 http://youtu.be/smAmDRK-tWY
문제풀이 by 황인철 http://youtu.be/4hoVKvk8dq0
10.4 Areas and Lengths in Polar Coordinates
문제풀이 by 곽주현 http://youtu.be/LRmasW9uqYY
10.5 Conic Section
http://matrix.skku.ac.kr/2014-Album/Quadratic-form/index.htm
문제풀이 by 변희성 http://youtu.be/ONItxvlsnb8
문제풀이 by 이한울 http://youtu.be/CZ9SHMtqVy4
Chapter 11. Vectors and the Geometry of Space
11.1 Three-Dimensional Coordinate Systems
문제풀이 by 김태현 http://youtu.be/_s_2T1VVob8
11.2 Vectors
문제풀이 by 오교혁 http://youtu.be/BFgh6irMqsc
11.3 The Dot Product
11.4 The Vector or Cross Product
11.5 Equations of Lines and Planes
문제풀이 by 구본우 http://youtu.be/lxuGE_Erthg
11.6 Cylinders and Quadric Surfaces
Chapter 12. Vector Valued Functions
12.1 Vector-Valued Functions and Space Curves
문제풀이 by 최양현 http://youtu.be/jvMI6OzdR_I
12.2 Calculus of Vector Functions
문제풀이 by 김동윤 http://youtu.be/VS5rPyOjP2I
12.3 Arc Length and Curvature
*12.4 Motion Along A Space Curve: Velocity and Acceleration
Chapter 13. Partial Derivatives
13.1 Multivariate Functions
문제풀이 by 구본우 http://youtu.be/As_0AYApHlM
13.2 Limits and Continuity of Multivariate Functions
13.3 Partial Derivatives http://youtu.be/LR89Ct3cEDY
문제풀이 by 김동윤 http://youtu.be/rSYLp1mSMXY
13.4 Differentiability and Total Differentials
문제풀이 by 김범윤 http://youtu.be/qDmCWBiXbIA
13.5 The Chain Rule http://youtu.be/r3dGYL1vkEU
문제풀이 by 김유경 http://youtu.be/vzN5By6qzvM
13.6 Directional Derivatives and Gradient http://youtu.be/o8L_ShRANjo
문제풀이 by 김태현 http://youtu.be/2_7TOUuzJoE
13.7 Tangent Plane and Differentiability http://youtu.be/uOf-5YHKGI4
문제풀이 by 서용태 http://youtu.be/GDkE8OqUvsk
13.8 Extrema of Multivariate Functions http://youtu.be/oDZUkOEszOQ
문제풀이 by 오교혁 http://youtu.be/FWmk_MasIjE
13.9 Lagrange Multiplier
문제풀이 by 이원준 http://youtu.be/YMGdQWBzyrI
Chapter 14. Multiple Integrals
14.1 Double Integrals http://youtu.be/jZ2pAmPZYOE
문제풀이 by 이인행 http://youtu.be/w8g9fgcEP4A
14.2 Double Integrals in Polar Coordinates http://youtu.be/olQgihl5aZg
문제풀이 by 이지석 http://youtu.be/jpsObxtZ50A
14.3 Surface Area http://youtu.be/p9R0TTLfBzk
14.4 Cylindrical Coordinates and Spherical Coordinates
문제풀이 by 최양현 http://youtu.be/F9u6pMubVRs
14.5 Triple Integrals http://youtu.be/r1tzH9Ibbqk
문제풀이 by 이인행 http://youtu.be/C-uPM3km96k
14.6 Triple Integrals in Cylindrical and Spherical Coordinates
14.7 Change of Variables in Multiple Integrals http://youtu.be/INn-bkgXYNg
Chapter 15. Vector Calculus
15.1 Vector Differentiation http://youtu.be/q0aVmUCXgTI
문제풀이 by 김동윤 http://youtu.be/iSUME4Q1WPM
15.2 Line Integrals http://youtu.be/wHINlpNXYaU
문제풀이 by 김범윤 http://youtu.be/ZdRjCfJeHM8
15.3 Independence of the Path http://youtu.be/jGGOL3QDj1Y
문제풀이 by 김유경 http://youtu.be/TreCe8ESEiU
15.4 Green’s Theorem in Plane http://youtu.be/WxdTbaSb_ZI
문제풀이 by 서용태 http://youtu.be/wLTHYaANwtI
15.5 Curl and Divergence http://youtu.be/IswmJUCTeNA
문제풀이 by 오교혁 http://youtu.be/j7F3xVNdHvA
15.6 Surface and Area http://youtu.be/xX6tNVpegbs
15.7 Surface Integrals http://youtu.be/nrzIrM4doLo
문제풀이 by 이원준 http://youtu.be/s_MRgW2By38
15.8 Stokes’ Theorem http://youtu.be/t4skc_PzJvg
15.9 Divergence Theorem http://youtu.be/3BmcFr81kuQ
문제풀이 by 최주영 http://youtu.be/vGMLoGWF1Is
[실습실] http://matrix.skku.ac.kr/Cal-Book/
Part I Single Variable Calculus
http://matrix.skku.ac.kr/Cal-Book/part1/part1.html
Part II Multivariate Calculus
http://matrix.skku.ac.kr/Cal-Book/part2/part2.html
[Grapher]
http://matrix.skku.ac.kr/cal-lab/sage-grapher-integral2.html
http://matrix.skku.ac.kr/cal-lab/sage-grapher-inverse.html
http://matrix.skku.ac.kr/cal-lab/cal-Newton-method.html
http://matrix.skku.ac.kr/cal-lab/sage-grapher-derivatives.html
http://matrix.skku.ac.kr/cal-lab/sage-grapher-integral.html
http://matrix.skku.ac.kr/cal-lab/sage-grapher-integral2.html
http://matrix.skku.ac.kr/cal-lab/SKKU-Cell-Matrix-Calculator.html
http://matrix.skku.ac.kr/cal-lab/sage-grapher-butterfly.html
http://matrix.skku.ac.kr/cal-lab/sage-grapher-cochleoid.html
http://matrix.skku.ac.kr/cal-lab/sage-grapher-dewdrop.html
http://matrix.skku.ac.kr/cal-lab/sage-grapher-epicycloid.html
http://matrix.skku.ac.kr/cal-lab/sage-grapher-flower.html
http://matrix.skku.ac.kr/cal-lab/sage-grapher-pinwheel.html
http://matrix.skku.ac.kr/cal-lab/sage-grapher-Gear-Curve.html
http://matrix.skku.ac.kr/cal-lab/sage-grapher-Bicorn.html
http://matrix.skku.ac.kr/cal-lab/sage-grapher-Cartesian-Oval.html
http://matrix.skku.ac.kr/cal-lab/sage-grapher-Double-Folium.html
http://matrix.skku.ac.kr/cal-lab/sage-grapher-Figure-Eight-Curve.html
http://matrix.skku.ac.kr/cal-lab/sage-grapher-Folium.html
http://matrix.skku.ac.kr/cal-lab/sage-grapher-Involute-of-a-Circle.html
http://matrix.skku.ac.kr/cal-lab/sage-grapher-Kappa-Curve.html
http://matrix.skku.ac.kr/cal-lab/sage-grapher-Lame-Curves.html
http://matrix.skku.ac.kr/cal-lab/sage-grapher-Lituus.html
http://matrix.skku.ac.kr/cal-lab/sage-grapher-Nephroid.html
http://matrix.skku.ac.kr/cal-lab/sage-grapher-Pearls-of-Sluze.html
http://matrix.skku.ac.kr/cal-lab/sage-grapher-Serpentine.html
http://matrix.skku.ac.kr/cal-lab/sage-grapher-Tricuspoid.html
http://matrix.skku.ac.kr/cal-lab/sage-grapher-Fermat-Spiral.html
http://matrix.skku.ac.kr/cal-lab/sage-grapher-Freeth-Nephroid.html
http://matrix.skku.ac.kr/cal-lab/sage-grapher-Durer-Shell-Curves.html
http://matrix.skku.ac.kr/cal-lab/sage-grapher-Newton-Diverging-Parabolas.html
http://matrix.skku.ac.kr/cal-lab/sage-grapher-Talbot-Curve.html
3. Linear Algebra (English)
[Linear Algebra Syllabus (선형대수학 수업계획서)]
http://matrix.skku.ac.kr/2017-Album/LA-syllabus.htm
Linear Algebra, First Class, Syllabus-Review https://youtu.be/43nhECDzfiE
(English Textbook) http://goo.gl/t3JcNP
[Lectures Recorded]
http://matrix.skku.ac.kr/2017-Album/2017-Spring-Lectures.htm
http://matrix.skku.ac.kr/2015-LA-FL/Linear-Algebra-Flipped-Class-SKKU.htm
Linear Algebra Lecture Note (English) http://matrix.skku.ac.kr/LA/
Linear Algebra Lecture Note (Korean) http://matrix.skku.ac.kr/LA-K/
Linear Algebra Simulations: http://matrix.skku.ac.kr/LinearAlgebra.htm
Chapter 1. Vectors
*1.1 Vectors in n-space and *1.2 Inner product and Orthogonality
1.3 Vector Equations of lines and planes https://youtu.be/MR1md8R1T_g
Chapter 2. Linear system of equations
2.1 Linear System of Equations, https://youtu.be/JbfSo5G6JR0
Review https://youtu.be/nhYG5uuGHqU
2.2 Gaussian and Gauss-Jordan elimination, https://youtu.be/ySncbrZTdMk
2.2–2.3 Exercise https://youtu.be/ySncbrZTdMk https://youtu.be/khbfoZBFfvA
2.4 Exercises, https://youtu.be/khbfoZBFfvA
Chapter 3. Matrix and Matrix Algebra
3.1 Matrix operation https://youtu.be/rDt3EOGl9lg
3.2 Inverse matrix https://youtu.be/o2iT6ZT5WIU
3.3 Elementary matrix https://youtu.be/DubGO81dTAI
3.4 (part 1) Subspace https://youtu.be/gNm7yzk8ess
3.4 (part 2) Linear independence https://youtu.be/LswYaDbj4ds
3.5 Solution set of a linear system and matrix https://youtu.be/7zZDGgPGE4s
3.6 Special matrices and Sec 3.8 Exs/Sol https://youtu.be/gve7cYW3W9I
*3.7 LU-decomposition http://youtu.be/lKJPnLCiAVU
Student Review : Ch3-Ch2-Ch1 https://youtu.be/m4ZEHknJMZY
Chapter 4. Determinant
4.1 Definition and Properties of the Determinants https://youtu.be/ltxi0hCUILg
4.2 Cofactor Expansion/ Appl of Determinants https://youtu.be/Yn5qu_062sA
4.3 Cramer's Rule https://youtu.be/rAmfnERqfU8
*4.4 Application of Determinant https://youtu.be/APsZ33BBOVs
4.5 Eigenvalues/Eigenvectors &4.6 Excercise https://youtu.be/s1OI74nr660
Chapter 5. Matrix Model
5.1 Lights out Game http://youtu.be/_bS33Ifa29s
5.2 Power Method http://youtu.be/CLxjkZuNJXw
5.3 Linear Model (Google) http://youtu.be/WNUoXLh8i_E
Project: http://youtu.be/coNq48CW6Pg
- Ch 5 Matrix Model 학생 발표 https://youtu.be/4u9LtmX7lvk
Chapter 6. Linear Transformations
6.1 Matrix as a Function (Transformation) https://youtu.be/Es4BfHnIq7g
6.2 Geometric Meaning of LT (part 1) https://youtu.be/V6m0PKQm6es
(part 2) https://youtu.be/qeRmhJQIphI
6.3 Kernel and Range https://youtu.be/7OfNTNl6IjI
6.4 Composition of LT and Invertibility https://youtu.be/Im7uaogKySw
*6.5 Computer Graphics with Sage https://youtu.be/45zSkGN7inw
6.6 Exercises https://youtu.be/pJgIaHpIhsM
Chapter 6. QnA Review https://youtu.be/snQsn2J_tuA
LA Midterm PBL 1 Presentation https://youtu.be/WG-HFdER5Ro
LA PBL and Ch6 and Ch4 Student Review https://youtu.be/xq4YyRtzTKg
http://matrix.skku.ac.kr/2016-album/LA-Sol-Ch-1-2-3-4-6/index.html
http://matrix.skku.ac.kr/LA-Lab/Solution/
http://matrix.skku.ac.kr/2016-album/LA-Main-Theorems/index.html
Sample Midterm Exam: http://matrix.skku.ac.kr/LA/2016-S-LA-Midterm-Final-Solution.pdf
LA Midterm Exam
http://matrix.skku.ac.kr/2017-Album/2017-S-LA-Midterm-Exam-Final-3.pdf
LA Midterm Exam Sol
http://matrix.skku.ac.kr/2017-Album/2017-S-LA-Midterm-Exam-Solution-Final3.pdf
LA Midterm Exam Sol
http://matrix.skku.ac.kr/2017-Album/LA-Midterm-Exam-Solution.htm (image)
2017 Spring LA Midterm Exam Review https://youtu.be/DOhahD4Nb44
Chapter 7. Dimension and Subspaces
7.1 and 7.2 (Review) Bases and dimensions, Basic spaces
7.3,7.4, 7.5, Rank-Nullity theorem, Rank theorem, Projection theorem
*7.6 Least square solution https://youtu.be/GwHh5lh5wEs
Grade/QnA/ Review: https://youtu.be/eEAHVs351u8
7.7 Gram-Schmidt orthonormalization process https://youtu.be/Px6Gaks9fXQ
* 7.8 QR-Decomposition; Householder
7.9 Coordinate vectors https://youtu.be/VR9FoZDQmAo
Chapter 8. Diagonalization
8.1 Matrix Representation of LT https://youtu.be/LpIR47W_stw
8.2 Similarity and Diagonalization https://youtu.be/wqrLcfSeL8Q
8.3 Diagonalization with orthogonal matrix https://youtu.be/5Sg-Edczw_g
8.4 Quadratic forms and Sec *8.5 Appl. https://youtu.be/mjAr3ddevE8
8.6 SVD and Pseudo-Inverse https://youtu.be/KU5l-XWDJuo
8.7 Complex eigenvalues and eigenvectors https://youtu.be/-l7uTfYHjFU
8.8 Hermitian, Unitary, Normal Matrices https://youtu.be/NRTmmmC-L9k
*8.9 Linear system of differential equations
http://www.hanbit.co.kr/EM/sage/1_chap6.html
Chapter 9. General Vector Spaces
9.1 Axioms of Vector Space, https://youtu.be/RnKjspG65AM
9.2 Inner product spaces; *Fourier Series, https://youtu.be/J0s8AkP4E38
9.3 Isomorphism, https://youtu.be/WiZZtF0c1hY
Chapter 10. Jordan Canonical Form
10.1 Finding the Jordan Canonical Form with a Dot Diagram
https://youtu.be/8fwPPOg8LW0 https://youtu.be/1E3wXN1oZyc
*10.2 Jordan Canonical Form and Generalized Eigenvectors,
https://youtu.be/YrRnCByzxNM https://youtu.be/yJ7n0icjtNA
10.3 Jordan Canonical Form and CAS, https://youtu.be/YrRnCByzxNM
학생 문제 풀이, https://youtu.be/y4173MpjoxE http://youtu.be/9-G3Fd2xOW0 Chapter 10 http://www.youtube.com/watch?v=adWzUKKmO2k
4. Linear Algebra (Korean)
[선형대수학 Korean Lectures – 우리말 강의 (동영상)]
PBL - Flipped Learning http://youtu.be/Mxp1e2Zzg-A
Lecture 1 Introduction http://youtu.be/w7IzR4nGa3Q
(Korean) http://matrix.skku.ac.kr/2015-Album/Big-Book-LinearAlgebra-Eng-2015.pdf
(디지털 교과서) http://matrix.skku.ac.kr/LA-K/
Chapter 1. Vectors
1.1 벡터 and 1.2 내적 http://youtu.be/aeLVQoPQMpE
1.3 벡터방정식 http://youtu.be/4UGACWyWOgA
Chapter 2. Linear system of equations
2.1 선형연립방정식 http://youtu.be/CiLn1F2pmvY
2.2 Gauss-Jordan 소거법 http://youtu.be/jnC66zvqHJI
Chapter 3. Matrix and Matrix Algebra
3.1 행렬연산 http://youtu.be/DmtMvQR7cwA
3.2, 3.3 역행렬과 기본행렬 http://youtu.be/GCKM2VlU7bw
3.4 부분공간 http://youtu.be/HFq_-8B47xM
3.5 해공간 3.6 특수행렬 http://youtu.be/daIxHJBHL_g
Chapter 4. Determinant
4.1 행렬식 http://youtu.be/DM-q2ZuQtI0
4.2 여인자 전개와 역행렬 http://youtu.be/XPCD0ZYoH5I
4.3 크래머의 법칙 4.4. Appl, 4.5 고유값, 고유벡터
Chapter 6. Linear Transformations
6.1 선형변환 http://youtu.be/YF6-ENHfI6E
6.2 선형변환의 기하학적 의미 http://youtu.be/cgySDj-OVlM
6.3 핵과 치역 http://youtu.be/9YciT9Bb2B0
6.4 선형변한의 합성과 역행렬 http://youtu.be/EOlq4LouGao
LA Midterm Exam http://youtu.be/R3F3VNGH8Oo
Chapter 7. Dimension and Subspaces
7.1 기저와 차원 http://youtu.be/or9c97J3Uk0
7.2 주요 부분공간들 https://youtu.be/BC9qeR0JWis
7.3 Rank Nullity Theorem http://youtu.be/ez7_JYRGsb4
7.4 계수정리 http://youtu.be/P4cmhZ3X7LY
7.5 정사영정리 http://youtu.be/GlcA4l8SmlM
7.6* 최소제곱해 https://youtu.be/BC9qeR0JWis
7.7 Gram-Schmidt의 정규직교화과정 http://youtu.be/gt4-EuXvx1Y
7.8* QR-분해, Householder transformations https://youtu.be/crMXPi2lgGs
7.9 좌표벡터 http://youtu.be/M4peLF7Xur0
Chapter 8. Diagonalization
8.1 선형변환의 행렬표현 http://youtu.be/gn5ve1tXD7k
8.2 닮음과 행렬의 대각화 http://youtu.be/xirjNZ40kRk
8.3 직교대각화 http://youtu.be/jimlkBGAZfQ
8.4 이차형식 http://youtu.be/vWzHWEhAd-k
8.5* Appl of Quadratic Function http://youtu.be/cOW9qT64e0g
8.6 Singular Value Decomposition https://youtu.be/ejCge6Zjf1M
8.7 and 8.8 복소고유값, 복소고유벡터, 정규행렬 http://youtu.be/8_uNVj_OIAk
Chapter 9. General Vector Spaces
9.1 and 9-2 일반벡터공간, 내적공간 http://youtu.be/m9ru-F7EvNg
9.3 동형사상 http://youtu.be/frOcceYb2fc
Chapter 10. Jordan Canonical Form
10.1 Jordan 표준형 http://youtu.be/NBLZPcWRHYI
10.3 Jordan Canonical Form with Sage http://youtu.be/LxY6RcNTEE0
(15 주차) 복습과 프로젝트 발표
Math, Art and 3D Printing http://youtu.be/olTfft1cuGw
PBL 보고서 by 김병찬 &우시명 http://youtu.be/hUDuQ8e8HsU
by 손홍철 http://youtu.be/woyS_EYWiDs
by 박민 http://youtu.be/E-5m65-8Ea8
by 전승준 http://youtu.be/JHT6aTQhr-A
by 김태용, 이학현, 이종화 http://youtu.be/JFVM4KRr2nc
(16주차) 기말고사
http://matrix.skku.ac.kr/2015-Album/CLA-Final-Sample-Exam.pdf
[실습실]
Manual http://matrix.skku.ac.kr/Lab-Book/Sage-Lab-Manual-2.htm
http://matrix.skku.ac.kr/2018-album/LA-Sec-1-1-lab.html
http://matrix.skku.ac.kr/2018-album/LA-Sec-1-2-lab.html
http://matrix.skku.ac.kr/2018-album/LA-Sec-1-3-lab.html
http://matrix.skku.ac.kr/2018-album/LA-Sec-2-1-lab.html
http://matrix.skku.ac.kr/2018-album/LA-Sec-2-2-lab.html
http://matrix.skku.ac.kr/2018-album/LA-Sec-3-1-lab.html
http://matrix.skku.ac.kr/2018-album/LA-Sec-3-2-lab.html
http://matrix.skku.ac.kr/2018-album/LA-Sec-3-3-lab.html
http://matrix.skku.ac.kr/2018-album/LA-Sec-3-4-lab.html
http://matrix.skku.ac.kr/2018-album/LA-Sec-3-5-lab.html
http://matrix.skku.ac.kr/2018-album/LA-Sec-3-6-lab.html
http://matrix.skku.ac.kr/2018-album/LA-Sec-4-1-lab.html
http://matrix.skku.ac.kr/2018-album/LA-Sec-4-2-lab.html
http://matrix.skku.ac.kr/2018-album/LA-Sec-4-5-lab.html
http://matrix.skku.ac.kr/2018-album/LA-Sec-6-1-lab.html
http://matrix.skku.ac.kr/2018-album/LA-Sec-6-2-lab.html
http://matrix.skku.ac.kr/2018-album/LA-Sec-6-3-lab.html
http://matrix.skku.ac.kr/2018-album/LA-Sec-6-4-lab.html
http://matrix.skku.ac.kr/2018-album/LA-Sec-7-1-lab.html
http://matrix.skku.ac.kr/2018-album/LA-Sec-7-2-lab.html
http://matrix.skku.ac.kr/2018-album/LA-Sec-7-3-lab.html
http://matrix.skku.ac.kr/2018-album/LA-Sec-7-4-lab.html
http://matrix.skku.ac.kr/2018-album/LA-Sec-7-7-lab.html
http://matrix.skku.ac.kr/2018-album/LA-Sec-7-9-lab.html
http://matrix.skku.ac.kr/2018-album/LA-Sec-8-1-lab.html
http://matrix.skku.ac.kr/2018-album/LA-Sec-8-2-lab.html
http://matrix.skku.ac.kr/2018-album/LA-Sec-8-3-lab.html
http://matrix.skku.ac.kr/2018-album/LA-Sec-8-8-lab.html
http://matrix.skku.ac.kr/2018-album/LA-Sec-9-1-lab.html
http://matrix.skku.ac.kr/2018-album/LA-Sec-9-3-lab.html
Problems in Chapter 1
Solved by 김민수 Revised by 배성준 Finalized by 김민수
Refinalized and Final OK by SGLee
Page 13 Exercise 1.2 No.7 (New)
Q : Graph the function. Specify the intervals where the function is increasing and where it is decreasing.
.
Sol)
Graph From sage
http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
Answer:
(i) Symmetric with respect to the -axis.
(ii) Increasing on and
.
(iii) Decreasing on and
. ■
Solved by 우시명 Revised by ShaoweiSun Finalized by 우시명
Final OK by SGLee
Calculus with Sage p.13 Chapter 1 Problem 1.2-10
Graph the following function. What symmetry, if any, do the graphs have?
Specify the intervals where the function is increasing and where it is decreasing.
Sol)
http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
1. It is not symmetric.
(See the graph to make sure it is not symmetric.)
2. [Find Decreasing Interval and Increasing Interval]
Use derivative to find the point where the graph starts to decrease or increase.
Find derivative : [CAS]
Derivative :
Solve the equation for :
Answer :
(,
) : Decreasing Interval
(,
) : Increasing Interval ■
Solved by 계성곤
Revised by 배성준
Finalized by 계성곤
Page 21 Exercise 1.3 (New) NO.6
Draw the graph of given function.
Sol)
http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
plot(exp(-1/sqrt(x^2+3)), x, -10, 10, color='blue')
http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
plot(exp(-1/sqrt(x^2+3)), x, -1000, 1000, color='blue')
The graph's asymptote is ■
Solved by 계성곤
Revised by 배성준
Finalized by 계성곤
Refinalized by 이송섭
Final OK by SGLee
Page 30 Exercise 1.4 (New) NO.12
Graph the function.
Sol)
http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
var('x')
plot((x^3-6)^(1/3), x, 2, 10, color='blue')
■
Problems in Chapter 2
Solved by 이송섭
Resolved by 배성준
Finalized by 이송섭
Refinalized and Final OK by SGLee
Page 47 Exercise 2.1 (Old) No.3
Find the following limit.
Sol)
Since and
,
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
limit(sin(x)/abs(cos(x)), x=pi/2)
+Infinity
Answer: ■
Solved by 변희성
Revised by 배성준
Refinalized and Final OK by SGLee
page 47 Exercise 2.1 4 (New)
Find the following limit or explain why the limit does not exist.
Sol)
If ,
.
If ,
=>
=> The limit does not exist. ■
Solved by 이송섭
Finalized by 배성준
Refinalized by 이송섭
Refinalized and Final OK by SGLee
P.49 Chaptor2.1 exercise14 (old)
Let .
Find all positive integer such that
.
Sol)
Then the limit should satisfy .
1) when ,
2) When ,
3) When and
is even,
4) When and
is odd,
Thus, only (3) satisfies the condition, that is .
Answer: ■
Solved by 이송섭
Revised by 우시명
Revesed by 배성준
Finalized by 이송섭
Refinalized by 이송섭
Final OK by SGLee
p.50 Chapter2.1 Exercise No.19(old)
19. Use the argument to prove that
Proof)
Let . [Find
> 0]
Take
If ,
Then .
whenever
We haver proved . ■
[side cal]
Solved by 배성준
Finalized by 이송섭
Final OK by SGLee
Page 50 Exercise 2.1 (New) No.19
Use the argument to prove that
.
Proof)
Let . [Find
> 0]
Take
If ,
Then .
whenever
We haver proved . ■
[side cal]
Epsilon Delta Proof
Solved by 배성준
Revised by 이송섭
Finalized by 문지호
Refinalized by 배성준
Final OK by SGLee
Page 50 Exercise 2.1 (New) No.20
17. Use the argument to prove that
if and
.
Proof)
Let , [Find
> 0]
Take
If ,
then
whenever
. █
(side cal)
Epsilon Delta Proof
Solved by 이송섭
Revised by 이송섭
Finalized by 이송섭
Final OK by SGLee
[1] 연속함수인 경우(아주 간단한 예)
Calculus with Sage P.51 Chapter 2.1-24 (Old).
Using the argument prove
Proof)
Let , [Find
> 0]
Take .
If ,
then .
whenever
. ■
(side cal)
.
Final OK by SGLee
[2] 연속함수인 경우(예)
Show .
Proof. ∀ >0 [Find
]
Let =
If |-
| <
,
then
( = )
=
■
<side cal.>
□
Final OK by SGLee
[3] 연속함수인 경우(예)
Show.
Proof. ∀ >0 [Find
]
Let =
If ,
then
( = )
=
=
=
=
■
<side cal.>
□
Epsilon Delta Proof
ReFinalized and Final OK by SGLee
[4] 연속함수인 경우 (min 기법 예)
Show .
Proof. ∀ >0 [Find
]
Let {
}
If ,
then =
■
<side cal.>
□
Epsilon Delta Proof
[4] 연속함수인 경우 (min 기법 예)
Show
Proof. ∀ε>0, Find δ
choose {
}
If
=
Show
Proof. ∀ε>0, Find δ
Let =min{
}
ReFinalized and Final OK by SGLee
[4] 연속함수인 경우 (min 기법 예)
Show .
Proof. ∀ >0 [Find
]
Let
If
then =
■
<side cal.>
Take .
If , then
.
=
□
ReFinalized and Final OK by SGLee
[7] 불연속인 점에서의 경우 limit (예)
Show .
Proof. ∀ >0 [Find
]
Let
.
If ,
then
=
■
<side cal.>
by (*)
and
□
https://sagecell.sagemath.org/ (*)
P1=plot(sqrt(3*x^3)*(4-cos(3/sqrt(x^3)), 0.01,2)
P2=plot(sqrt(3*x^3)*(5), 0.01,2, color='red')
P3=plot(sqrt(3*x^3)*(3), 0.01,2, color='red')
show(P1+P2+P3)
Final OK by SGLee
[8] 발산의 경우 limit (예)
Show .
Proof. ∀ Large number ,[Find
]
Let (
)
If ,
then
■
<side cal.>
Since ,
P1=plot(1/(x-5)^2, -10,10)
show(P1)
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
Solved by 이송섭
Finalized by 김민수
Final OK by SGLee
Page 63 Exercise 2.2 No.18 (New)
1. Prove that there is a root of the given equation in the specified interval by using the Intermediate Value Theorem.
Proof)
Let
Then .
Since is a real-valued continuous function on the interval
and
, there is a root
such that
by the intermediate value theorem. █
[Sage] 그림을 그려보면 1과 2 사이에서 근이 존재함을 확인 할 수 있다.
True
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
Solved by 계성곤
Finalized by 이송섭
Final OK by SGLee
Page 63 Exercise 2.2 (New) NO.18
Prove that there is a root of the given equation in the specified interval by using the Intermediate Value Theorem.
Proof)
Let .
The function is continuous on the domain
.
We can easily check and
.
By the intermediate value theorem, there exists s.t.
.
has at least one real root. ■
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
var('x')
f(x)=sqrt(3*x^2-x^3)-1.5
P=plot(f,0,3)
show(P, aspect_ratio=1)
bool(f(1)<0)
True
bool(f(2)>0)
True
Solved by 배성준 Revised by 계성곤 Revised by 배성준 Finalized by 배성준
Final OK by SGLee
Page P64 Exercise 2.2 (New) No.20
Prove that there is a root of the given equation in the specified interval by using the Intermediate Value Theorem.
, (0,1)
Proof)
Let =
.
is continuous on the domain
.
We can easily check and
.
By the intermediate value theorem, there exists s.t.
.
This implies that there is a root of the given equation in the specified interval. ■
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
var('x')
f(x)=(ln(2*x^2))^2/(exp(x^2)+3/x)
g(x)=x^6
p1=plot(f(x)-g(x), 0, 1, exclude=[0], ymax=1, ymin=-1)
show(p1)
True
True
Solved by 문지호
Fixed by 이송섭
Finalize by 문지호
Final OK by SGLee
Page 64 exercise 23 (old)
Show that the following equation has at least one real root.
Proof)
Define a function .
The function is continuous on the domain
.
We can easily check > 0 and
< 0.
By the intermediate value theorem, there exists s.t.
.
has at least one real root. ■
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
sage: P = plot(e^x, x, 0, 1, linestyle="--", color='red')
sage: Q = plot(4*sin(x),x,0, 1)
sage: show(P+Q)
[설명] 과
가 [0, 1] 사이의 한점에서 만나는 것을 두 가지 방법으로 쉽게 확인 할 수 있었다. Solved by 김민수
Solved by 계성곤
Page 64 Exercise 2.2 (New) NO.23
Show that the following equation has at least one real root.
Sol)
we may draw both and
in one graph to find intersections. It shows the function has one real root in 0<x<1.
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
p1=plot(ln(x)+3, x, 0, 9, color='blue')
p2=plot(4*cos(x), x,0, 9, color='red')
show(p1+p2, ymax=5, ymin=-4)
The following Sage commands give the value of the intersection in the interval 0<x<1.
find_root(ln(x)+3==4*cos(x), 0, 1)
Answer : 0.8024194649325627■
Problems in Chapter 3
Solved by 우시명
Revised by Shaowe Sun
Finalized by 우시명
Final OK by SGLee
Calculus with Sage p.70 Chapter 3.1 Problem 5 (New)
Differentiate the following function, if it exists.
Sol) Use sage to find derivative.
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
var('t')
f(t)=(4*t-3)^3*(3*t-2)^2*(2*t-1)
diff(f(t),t).show()
Answer :
■
Solved by 배성준
Revised by Shaowe Sun
Finalized by 배성준
Final OK by SGLee
Page 70 Chapter 3.1 Exercise No 7. (New)
Differentiate the following function using Definition, if it exists.
Sol)
■
Solved by 우시명
Finalized by 이송섭
Final OK by SGLee
Calculus with Sage p.70 Chapter 3.1 Problem 7 (New)
Differentiate the following function, if it exists.
Sol) Use sage and find derivative.
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
var('t')
f(t)=t^(t-1)/t+1
diff(f(t),t)
((t - 1)/t + log(t))*t^(t - 1)/t - t^(t - 1)/t^2
Answer : ■
Solved by 김요섭
Finalize by 문지호
Refinalized and Final OK by SGLee
Chapter 3.1 page 70 exercise 8 (old)
Is the function
differentiable at ?
Sol)
The function is differentiable at
if and only if
exists.
=>
The function is differentiable at
■
Solved by 계성곤
Finalized by 계성곤
Refinalized by 이송섭
Final OK by SGLee
Page 83 Exercise 3.2 (New) NO.7
The normal line to a curve at a point
is the line that passes through
and is perpendicular to the tangent line to
at
. Find an equation of the normal line to the curve
at the point (0, 1)
Sol)
Slope of normal line: -1
Since normal line L pass through point (0,1)
Answer: Normal line is ■
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
f(x)=1+e^x*sin(x)
df(x)=diff(f(x),x)
y(x)=-1/df(0)*x+1
y(x)
Answer : -x+1
p1=plot(f(x),x,-5,5, color='blue');
p2=plot(y(x),x,-5,5, color='red');
show(p1+p2,ymax=10,ymin=-5)
Solved by 계성곤
Revised by 김요섭
Finalized by 계성곤
Page 84 Exercise 3.2 (New) NO.9
Let . Find the values of
and
that make
differentiable everywhere.
Sol)
Note that is differentiable everywhere except
=2. For
to be differentiable at 2,
, so
. And also
have to be continuous at 2.
, so
,
Therefore, and
.■
Solved by 계성곤
Finalized by 이송섭
Final OK by SGLee
Page 85 Exercise 3.2 (New) NO.14
Find derivatives of the following function.
Sol)
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
f(x)=(tan(x))^2*csc(x)/exp(x)
df(x)=diff(f(x),x)
print df(x)
Answer :
-e^(-x)*tan(x)^2*csc(x)*cot(x) + 2*(tan(x)^2 + 1)*e^(-x)*tan(x)*csc(x) - e^(-x)*tan(x)^2*csc(x) ■
Solved by 우시명
Finalized by 이송섭
Final OK by SGLee
Calculus with Sage p.85 Chapter3 Problem3.2-15
Find derivatives of the following functions.(New)
Sol)
Use Sage to find its derivative.
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
-(log(x)*sin(x) - cos(x)/x)*sin(x)/x^(-cos(x)) + cos(x)/x^(-cos(x))
Answer: ■
Solved by 우시명
Finalized by 문지호
Final OK by SGLee
Calculus with Sage p.108 Chapter 3.3 Problem 12 (New)
Find the th derivative of
.
Sol)
Find etc. And predict
.
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
var('x')
f(x)=x^4+2/(2-x)
print "f'(x)=", diff(f(x), x).factor()
print "f''(x)=", diff(f(x), x, 2).factor()
print "f^(3)(x)=", diff(f(x), x, 3).factor()
print "f^(4)(x)=", diff(f(x), x, 4).factor()
print "f^(5)(x)=", diff(f(x), x, 5).factor()
print "f^(6)(x)=", diff(f(x), x, 6).factor()
print "f^(7)(x)=", diff(f(x), x, 7).factor()
print "f^(8)(x)=", diff(f(x), x, 8).factor()
print "f^(9)(x)=", diff(f(x), x, 9).factor()
f'(x)= 2*(2*x^5 - 8*x^4 + 8*x^3 + 1)/(x - 2)^2
f''(x)= 4*(3*x^5 - 18*x^4 + 36*x^3 - 24*x^2 - 1)/(x - 2)^3
f^(3)(x)= 12*(2*x^5 - 16*x^4 + 48*x^3 - 64*x^2 + 32*x + 1)/(x - 2)^4
f^(4)(x)= 24*(x^5 - 10*x^4 + 40*x^3 - 80*x^2 + 80*x - 34)/(x - 2)^5
f^(5)(x)= 240/(x - 2)^6
f^(6)(x)= -1440/(x - 2)^7
f^(7)(x)= 10080/(x - 2)^8
f^(8)(x)= -80640/(x - 2)^9
f^(9)(x)= 725760/(x - 2)^10
Answer : ■
Solved by 변희성
Finalized by 계성곤
Page 109 Exercise 3.3 (New) NO.17
In problems below, find
Sol)
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
var('x')
f(x)=ln((x-1)^(1/3)/(x^2-1)^(1/2))
diff(f(x),x)
Answer : -1/3*sqrt(x^2 - 1)*(3*(x - 1)^(1/3)*x/(x^2 - 1)^(3/2) - 1/((x - 1)^(2/3)*sqrt(x^2 - 1)))/(x – 1)^(1/3)■
Solved by 계성곤
Page 109 Exercise 3.3 (New) NO.19
In problem, find .
Sol)
var('x')
diff((csc(x))^(sqrt(x+3)))
Answer :
-1/2*(2*sqrt(x + 3)*cot(x) - log(csc(x))/sqrt(x + 3))*csc(x)^sqrt(x + 3)
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
■
Solved by 김요섭
Finalize by 문지호
Refinalize by 계성곤
Final OK by SGLee
Chapter 3.3 Page 109 exercise 21 (new)
Find if
.
Sol)
Answer:
■
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
var('x');
df(x)=diff(x^(ln(x)),x);
ddf(x)=diff(df(x), x);
df(x), ddf(x)
show(df(x))
show(ddf(x))
Answer
p.s. Chain rule was used each time when differentiation is done.
Solved by 계성곤
Page 109 Exercise 3.3 (New) NO.21
Find if
Sol)
var('x')
df(x)=diff((arcsec(x))^(arctan(x)),x);
df(x)
Answer : (log(arcsec(x))/(x^2 + 1) + arctan(x)/(sqrt(-1/x^2+
1)*x^2*arcsec(x)))*arcsec(x)^arctan(x)
ddf(x)=diff(df(x),x)
ddf(x)
Answer : (log(arcsec(x))/(x^2 + 1) + arctan(x)/(sqrt(-1/x^2 +
1)*x^2*arcsec(x)))^2*arcsec(x)^arctan(x) - (2*x*log(arcsec(x))/(x^2 +
1)^2 + 2*arctan(x)/(sqrt(-1/x^2 + 1)*x^3*arcsec(x)) - 2/(sqrt(-1/x^2 +
1)*(x^2 + 1)*x^2*arcsec(x)) + arctan(x)/((-1/x^2 + 1)*x^4*arcsec(x)^2) +
arctan(x)/((-1/x^2 + 1)^(3/2)*x^5*arcsec(x)))*arcsec(x)^arctan(x)
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/ ■
Solved by 우시명
Finalized by 계성곤
Page 109 Exercise 3.3 (New) NO.22
Find and
of the following functions.
,
Sol)
To find , derive
about
and derive
about
. Using foregoing two, find
var('t, a, b')
x(t)=a*sec(t)
y(t)=b*tan(t)
dx(t)=diff(x(t), t)
dy(t)=diff(y(t), t)
dydx=dy(t)/dx(t)
print "dy/dx=", dydx
Answer : dy/dx= (tan(t)^2 + 1)*b/(a*tan(t)*sec(t))
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
To find , derive two times and follow forgoing process.
var('t, a, b')
x(t)=a*sec(t)
y(t)=b*tan(t)
dx(t)=diff(x(t), t)
dy(t)=diff(y(t), t)
dydx=dy(t)/dx(t)
print "d2y/dx2=", (diff(dydx, t)/dx(t))
Answer : d2y/dx2= ((tan(t)^2 + 1)*b/(a*sec(t)) - (tan(t)^2 + 1)^2*b/(a*tan(t)^2*sec(t)))/(a*tan(t)*sec(t))
https://sagecell.sagemath.org/ ■
Solved by 변희성
Finalized by 배성준
Refinalized by 이송섭
Final OK by SGLee
P.110 Chapter 3.3 Exercises problem 30(New)
Given , find y'' at the point (1,2).
Sol)
Answer: ■
Solved by 우시명
Finalized by 문지호
Refinalized and Final OK by SGLee
Calculus with Sage p.119 Chapter 3.4 Problem 1 (New)
Use differential to approximate .
Sol)
Let .
Then at
.
Thus,
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
var('x, dx');
f(x)=(x+36)^(1/2);
dy(x)=diff(f(x),x)*dx;
(f(0)+dy(x=0, dx=7)).n()
Answer : 6.58333333333333 ■
Solved by 계성곤
Finalized by 이송섭
Refinalized and Final OK by SGLee
Page 119 Exercise 3.4 (New) NO.2
Use differential to approximate the following quantity.
Sol)
Let .
Then
Thus,
Set and
at
Answer: ■
Solved by 변희성
Finalized by 계성곤
Refinalized by 이송섭
Final OK by SGLee
Page 121 Exercise 3.4 (New) NO.12
Water is being pumped at a rate of 10 liters per minute into a tank shaped like a globe. The tank has a radius 10 meters. How fast is the water level rising when the depth of the water is 15 meters?
Sol)
The tank is shaped like a globe. So in 15 meters, the surface is above the hemisphere.
Answer: (meter/minute) ■
Problems in Chapter 4
Solved by 우시명 Revised by 변희성 Finalized by 문지호
Revised by 배성준 Finalized by 문지호
Final OK by SGLee
Calculus with Sage p.132 Chapter 4.1 Problem 6 (New)
Find all critical numbers of the given function.
Sol)
Therefore critical numbers of are
.
[CAS] Draw the graph by using Sage.
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
Answer: critical numbers of are
. █
Solved by 문지호
Finalized by 배성준
Final OK by SGLee
Page 132. Ch4.1 Exercise No 8. (New)
2. Find all critical numbers of the given function.
Sol)
=
=> when
(
)
Critical numbers : (
)
[CAS] Draw the graph by using Sage.
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
Answer: (
) █
Solved by 이수헌
Revised by Sun Shaowei
Finalized by 문지호
Final OK by SGLee
Calculus with Sage p.134 Chapter 4.1 Problem 16(New)
Find the intervals where the function is increasing or decreasing.
Sol)
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
var('x')
f=(x^2)*exp(x^2)
p1=plot(f, -2, 2, ymax=2, ymin=-2)
df=diff(f)
p2=plot(df, -2, 2, ymax=2, ymin=-2)
show(p1+p2)
show(df)
is an even function and
is an odd function.
Answer :
Increasing Interval:
Decreasing Interval: ■
Solved by 이수헌
Revised by Sun Shaowei
Finalized by 문지호
Final OK by SGLee
Calculus with Sage p.134 Chapter 4.1 Problem 18 (New)
Prove the inequality.
Proof)
So, for
.
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
var('x')
p1=plot(x*exp(2*x))
p2=plot((exp(2*x)-1)/2, color='red')
p3=plot(x, color='yellow')
show(p1+p2+p3, ymax=4)
Blue line : ,
Red line :
Yellow line : ■
Solved by 우시명
revised by 변희성
Finalized by 배성준
Refinalized and Final OK by SGLee
Calculus with Sage p.135 Chapter 4.1 Problem 20 (NEW)
Prove the inequality.
Sol)
[CAS] Draw the graph of
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
In this graph, when
.
■
Solved by 우시명
revised by 변희성
Fianlized by 배성준
Refinalized and Final OK by SGLee
Calculus with Sage p.135 Chapter 4.1 Problem 23 (New)
Prove the inequality using the Mean Value Theorem.
Proof)
Let .
By the Mean Value Theorem there exist in
such that
Since for all
,
. ■
[CAS] Draw the graph of .
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
var('x')
f=sin(x)-sin(x+1)
plot(f,-100,100,color='red')
Solved by 우시명
revised by 변희성
Finalized by 배성준
Refinalized and Final OK by SGLee
Calculus with Sage p.135 Chapter 4.1 Problem 20 (New)
Prove the inequality.
Proof)
[CAS] Draw the graph of
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
when
■
Solved by 우시명
revised by 변희성
Finalized by 배성준
Refinalized and Final OK by SGLee
Calculus with Sage p.145 Chapter 4.2 Problem 4 (New)
Find the local maximum and minimum values of . In addition, find the intervals on which
is increasing and decreasing, and the intervals of concavity and the inflection points, sketch a graph of
.
Sol)
[CAS] Draw the graph, and find the point or interval.
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
Answer:
(a) Local maximum : , Local minimum: Not exist;
(b) Increase Interval: (, 0); Decreasing Interval: (0,
)
(c)
in ,
So, there is no inflection point on the interval .
The graph is concave downward(위로 볼록) on (,
) ■
Solved by 이수헌
Revised by 우시명
Finalized by Sun Shaowei
Final OK by SGLee
Calculus with Sage p.146 Chapter 4.2 Problem 10 (New)
Find the inflection points of . In addition, find intervals in which the graph of
is concave upward or concave downward.
Sol)
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
Answer:
(a) Inflection Point at
(b) Concave up on
Concave down on ■
Solved by 이수헌
Revised by 우시명
Finalized by Sun Shaowei
Final OK by SGLee
Calculus with Sage p.146 Chapter 4.2 Problem 11 (New)
Find the inflection points of In addition, find intervals in which the graph of is concave upward or concave downward.
Sol)
if
or
,
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
var('x')
f=plot(e^(-(x^4)),x, xmax=3,xmin=-3)
show(f)
Answer:
(a) Inflection points : and
(b) Concave down on
Concave up on ■
Solved by 이수헌
Revised by 문지호
Finalized by 문지호
Refinalized and Final OK by SGLee
Calculus with Sage p.147 Chapter 4.2 Problem 12 (New)
Find the vertical and horizontal asymptote of .
Sol)
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
var('x')
f = (x^2)/(x^2-4)
p1 = plot(f, -4, 4)
p2 = plot(1, -4, 4, linestyle="--", color='red')
show(p1+p2, ymax=10, ymin=-10)
,
,
Answer: Vertical asymptotes : , Horizontal asymptote :
. ■
Solved by 우시명
revised by 변희성
Finalized by 배성준
Final OK by SGLee
Calculus with Sage p.147 Chapter 4.2 Problem 12 (New)
Find the vertical and horizontal asymptotes of .
,
Sol)
Draw the graph
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
f=sqrt(x-6)/x^(2)
plot(f,0,70)
Answer: vertical asymptote : No, horizontal asymptote : y=0. ■
Solved by 문지호
Revised by Saowei Sun
Finalized by 배성준
Refinalized and Final OK by SGLee
Page 149. Ch4.2 Exercise No 24. (Old)
Prove the Concavity Test.
Concavity Test
Let be a function whose second derivative extists on an open interval
.
(i) If for all
in
,
then the graph of is concave upward (위로 오목) on
.
(증가율이 점점 커진다는 의미)
(ii) If for all
in
,
then the graph of is concave downward (아래로 오목) on
.
|
|
Proof)
(i) BWOC (By the Way Of Contradiction)
Suppose is not concave upward on
(when
for all
in
,).
=> There are SOME such that
and
.
By the mean value theorem, for some
.
at
. It occurs a contradiction.
: concave upward on
.
(ii) Similarly. █
Solved by 문지호
revised by 변희성
Finalized by 계성곤
Final OK by SGLee
Page 149. Chapter 4.2 Exercise 25 (New)
Use CAS to find and
when
Sol)
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
var('x')
f=(4*x^sqrt(2)-1)*sin(x)
df=diff(f,x)
ddf=diff(df,x)
show(df)
show(ddf)
Answer:
■
Solved by 문지호
Revised by 계성곤
Finalized by 배성준
Final OK by SGLee
Page 155. Chapter 4.3 Exercise 14 (Old)
Find .
Sol)
Apply L'Hospital's rule for a form of type .
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
var('x')
f=(x^3-2*x^2+2*x-1)/(x^3-x^2)
P1=plot(f, -0.5,1.5, ymax=2)
P2=plot(1,-0.5,1.5, linestyle='--', color='red')
show(P1+P2)
limit(f,x=1)
Answer: Limit is 1 ■
Solved by 우시명
revised by 변희성
Finalized by 배성준
Final OK by SGLee
Calculus with Sage p.155 Chapter 4.3 Problem 16 (New)
Find the following limit.
Sol)
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
1
Answer : 1 ■
Solved by 문지호
Finalized by 이송섭
Final OK by SGLee
Page 156. Ch4.3 Exercise No 26. (New)
Find ,
.
Sol-1)
= (by L'Hospital's rule)
█
Sol-2)
=> (since
is a continuous function, )
Answer : █
Solved by 문지호
Revised by 계성곤
Finalized by 계성곤
Final OK by SGLee
Page 157. Chapter 4.3 Exercise 29 (Old)
Let be a continuous function with
and
.
Find .
Sol 1)
Sol 2) Apply L'Hospital's theorem, since and
Answer: ■
Solved by 문지호
Finalized by 문지호
Final OK by SGLee
p.170 Chapter 4.5 Exercise No.13 (new)
Compute , the third approximation to the root of the given equation using Newton's method with the specified initial approximation
.
,
Sol)
http://matrix.skku.ac.kr/cal-lab/cal-Newton-method.html
Answer: █
Problems in Chapter 5
Solved by 배성준
Revised by 김요섭
Finalized by 문지호
Final OK by SGLee
Page 177 Exercise 5.1 (New) No.1
Find the area under the curve from 0 to 5.
Sol)
Thus the length of each sub-interval is and the
th sub-interval is given by
. now we apply the right end formula to find required area.
Side Calculus)
Answer: ■
http://matrix.skku.ac.kr/cal-lab/Area-Sum.html : Riemann Sum을 이용하여 적분의 근사값을 구하는 과정 시각화 를 이용하여 확인할 수 있다.
Solved by 문지호
ReSolved by 김요섭
Revised by 이송섭
Fianllized by 우시명
Final OK by SGLee
p.177 Chapter 5.1 exercise No.2(new)
2. (New) Find the area of the region under the graph of from 0 to 2.
Sol-1)
■
Sol-2)
[CAS]
https://sagecell.sagemath.org/
1/2*(e^4 + 1)*e^(-2) - 1
Answer: ■
Solved by 배성준
Revised by 김요섭
Finalized by 문지호
Final OK by SGLee
Page 177 Exercise 5.1 (New) No.3
Find the area under the curve from
to
, where
.
Sol)
when
=>.
Answer: █
Solved by 배성준
finalized by 김요섭
Final OK by SGLee
Page 188 Exercise 5.2 (New) No.1
Find the Riemann sum by using the Midpoint Rule with the given value of to approximate the integral.
,
sol)
Let . With
the interval width is
and midpoints are
for
. So the Riemann sum is
■
http://matrix.skku.ac.kr/cal-lab/Area-Sum.html : Riemann Sum을 이용하여 적분의 근사값을 구하는 과정 시각화 를 이용하여 확인할 수 있다.
Solved by 변희성
Revised by 우시명
Finalized by 배성준
Final OK by SGLee
Calculus with Sage p.188 Chapter 5.2 Problem 1 (New)
Find the Riemann sum by using the Midpoint Rule with the given value of n to approximate the integral.
Sol)
Let . Also,
, and midpoints are 4.5, 7.5, 10.5.
So, the Riemann sum is
Answer: ■
http://matrix.skku.ac.kr/cal-lab/Area-Sum.html : Riemann Sum을 이용하여 적분의 근사값을 구하는 과정 시각화 를 이용하여 확인할 수 있다.
Solved by 계성곤
Revised by 배성준
Finalized by 김민수
Final OK by SGLee
Page 188 Exercise 5.2 (New) NO.4
8. Find the Riemann sum by using the Midpoint Rule with the given value of to approximate the integral.
,
Sol)
Let . With
the interval width is
and midpoints are
(
)
So the Riemann sum is
=
Answer : ■
http://matrix.skku.ac.kr/cal-lab/Area-Sum.html : Riemann Sum을 이용하여 적분의 근사값을 구하는 과정 시각화 를 이용하여 확인할 수 있다.
Solved by 김요섭
Revised by 이송섭
Finallized by 우시명
Refinalized by 배성준
Final OK by SGLee
p.188 Chapter5.2 No.5 (new)
5. (New) Express the limit as a definite integral on the given interval.
Sol)
then,
.
Answer: ■
http://matrix.skku.ac.kr/cal-lab/Area-Sum.html : Riemann Sum을 이용하여 적분의 근사값을 구하는 과정 시각화 를 이용하여 확인할 수 있다.
Solved by 배성준
Revised by 김요섭
Finalized by 계성곤
Final OK by SGLee
Page 188 Exercise 5.2 (New) No.6
Express the limit as a definite integral in the given interval.
, [1, 6]
Sol)
■
http://matrix.skku.ac.kr/cal-lab/Area-Sum.html : Riemann Sum을 이용하여 적분의 근사값을 구하는 과정 시각화 를 이용하여 확인할 수 있다.
Solved by 계성곤
Finalized by 배성준
Final OK by SGLee
Page 189 Exercise 5.2 (New) NO.8
Express the limit as a definite integral on the given interval.
, [2, 15]
Sol)
=
=
Answer : ■
http://matrix.skku.ac.kr/cal-lab/Area-Sum.html : Riemann Sum을 이용하여 적분의 근사값을 구하는 과정 시각화 를 이용하여 확인할 수 있다.
Solved by 문지호
Revised by 김요섭
Finalized by 배성준
Final OK by SGLee
p.189 Chapter 5.2 Exercise No.12 (Old)
Determine whether the statement is true or false. If it is true, explain why. If it is false, give a counter example.
If is differentiable on
, then
Sol)
Theorem 1 : If function is continuous on
, then
is integrable on
.
Since is integrable on
,
is continuous on
by Theorem 1.
And by property 2(page 185), is true.
Answer: True █
Solved by 김요섭
Revised by 이송섭
Finalized by 우시명
Refinalized by 이송섭
Final OK by SGLee
p.189 Chapter5.2 exercise No.16
Show that if and
are continuous and
and
, then
.
Sol1)
Let and
and
are continuous, so
and
exist.
So ■
Solved by 변희성
Revised by 우시명
Finalized by 배성준
Final OK by SGLee
Calculus with Sage p.189 Chapter 5.2 Problem 19 (New)
Evaluate the intergral. (You should mention which method you use.)
Sol)
■
[CAS] Draw the graph.
https://sagecell.sagemath.org/
var('x')
f(x)=3*x+5
p1=plot(f(x), (x,-10,-5))+plot(f(x), (x,-5,-5/3), fill=true)+plot(f(x), (x,-5/3,10), fill=true)
p2=parametric_plot((-5,x),(x,-15,40), linestyle='--')
p3=parametric_plot((10,x),(x,-15,40), linestyle='--')
show(p1+p2+p3)
Solved by 문지호
Finalized by 문지호
Final OK by SGLee
p. 190 Chapter 5.2 Exercise 20 (New)
Evaluate the integral. (You should mention which method you use)
Sol)
[FTC] Find the anti-derivative of the integrand.
■
[CAS] https://sagecell.sagemath.org/
var('x,t');
f(x)=(e-1)*x^2-3
p1=plot(f(x),(x,-1,1))+plot(f(x),(x,1,e),fill="axis")+plot(f(x),(x,e,4))
p2=parametric_plot((1,t),(t,0,45),linestyle='--')
p3=parametric_plot((e,t),(t,0,45),linestyle='--')
show(p1+p2+p3)
print integral(f(x),x,1,e)
-10/3*e - 1/3*e^3 + 1/3*e^4 + 10/3
Answer: ■
Solved by 변희성
Revised by 우시명
Finalized by 문지호
Final OK by SGLee
Calculus with Sage p.190 Chapter 5.2 Problem 21
Evaluate the intergral. (You should mention which method you use.)
Sol)
[CAS] Draw the graph.
https://sagecell.sagemath.org/
var('x');
f(x)= -x^2-x+6
print integral(f(x),x,-3,6)
plot(f(x),(x,-5,0))+plot(f(x),(x,-3,6),fill=true)+plot(f(x),(x,6,9))
Answer: ■
Solved by 배성준
Revised by 김요섭
Finalized by 계성곤
Refinalized and Final OK by SGLee
Page 191 Exercise 5.2 (New) No.25
Evaluate the integral by interpreting it as a sum of the areas.
Sol)
Let
=>
=>
Since , let
and
.
=> and
=>
Answer: ■
Solved by 계성곤
Finalized by 김민수
Refinalized by 계성곤
Refinalized by 우시명
Final OK by SGLee
Page 191 Exercise 5.2 (New) NO.26
Evaluate the integral by interpreting it as a sum of the areas.
Sol)
Let
⇔
and
∴
Answer : ■
Solved by 계성곤
Finalized by 김민수
Final OK by SGLee
Page 191 Exercise 5.2 (New) NO.28
Prove that
Proof)
By using the end point rule,
=
=
=
∴
Answer : ■
http://matrix.skku.ac.kr/cal-lab/Area-Sum.html : Riemann Sum을 이용하여 적분의 근사값을 구하는 과정 시각화 를 이용하여 확인할 수 있다.
Solved by 김요섭
Revised by 이송섭
Finallized by 우시명
Refinalized by 배성준
Revised by 문지호
Re Finalize by 문지호
Final OK by SGLee
p.192 Chapter5.2 Exercise No.32(new).
Verify the inequality
Proof)
Let , and define
the
-th derivative function of
.
=>
for
=> (
)
Therefore .
We have proved that . ■
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/ 이용해서 보일 수 있다.
Solved by 김요섭
Revised by 김민수
Finalized by 계성곤
Refinallized by 우시명
Final OK by SGLEE
Page 199 Exercise 5.3 (New) NO.6
6. (New) Find the derivative of the function.
=
Sol)
Answer : ■
Solved by 계성곤
Finalized by 김민수
Final OK by SGLee
Page 199 Exercise 5.3 (New) NO.7
Find the derivative of the function.
Sol)
Answer : ■
Solved by 배성준
finalized by 김요섭
Final OK by SGLee
Page 199 Exercise 5.3 (New) No.8
Calculate the integral using Part 2 of the FTC.
Sol)
Answer: ■
Solved by 이송섭
Revised by 문지호
Finalized by 계성곤
Final OK by SGLee
p.200 Chapter 5.3 exercise No.13 (new)
Let and
Find
.
Sol)
Let . Then,
Answer: █
Solved by 문지호
Finalized by 배성준
Final OK by SGLee
p. 201 Chapter 5.3 Exercise 18 (New)
When where
, find
.
Sol)
Since ,
.
Let .
=>
=>
=>
Answer: ■
Solved by 김요섭
Revised by 계성곤
Finalized by 문지호
Final OK by SGLee
Page 207 Exercise 5.4 (New) NO.2
Verify by differentiation that the formula is correct.
Proof-1)
Let . Then
.
.
█
Proof-2)
█
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/ 이용해서도 구할 수 있다.
Solved by 김요섭
Revised by 계성곤
Finalized by 문지호
Final OK by SG LEE
Page 207 Exercise 5.4 (New) NO.2
Verify by differentiation that the formula is correct.
Sol)
Let
⟹
∴ (
is an integral constant.)
Answer : ■
Solved by 배성준
finalized by 김요섭
Refinalized and Final OK by SGLee
Page 207 Exercise 5.4 (New) No.3
Verify by differentiation that the formula is correct.
Proof)
Let (
). Then
.
Since ,
When ,
; when
,
.
=>
Therefore ■
Solved by 변희성
Revised by 문지호
Finalized by 계성곤
Re fianlized by 배성준
Final OK by SGLee
p.207 Chapter 5.4 exercise No.3(new)
Verify by differentiation that the formula is correct.
Proof-2)
Let . Then
.
.
Proof-1)
Answer) █
Solved by 변희성
Revised by 문지호
Finalized by 계성곤
Refinalized 배성준
Final OK by SGLee
p.207 Chapter 5.4 exercise No.4 (new)
Verify by differentiation that the formula is correct.
Proof)
Let . Then
.
.
.
█
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/ 이용해서도 구할 수 있다.
Solved by 문지호
Finalized by 배성준
Final OK by SGLee
p. 208 Chapter 5.4 Exercise 20 (Old)
Evaluate the integral.
Sol)
Substitute to
Woframalpha :
Answer: ■
Solved by 문지호
Finalized by 이송섭
Final OK by SGLee
p. 217 Chapter 5.5 Exercise 9 (New)
Find the indefinite integral.
Sol)
Let then
.
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
Answer: ■
Solved by 문지호
Finalized by 배성준
Final OK by SGLee
p. 218 Chapter 5.5 Exercise 20 (New)
Evaluate the definite integral, if it exists.
Sol)
Let then
.
Since this is even function,
.
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
Answer: ■
Solved by 김요섭
Revised by 배성준
Finalized by 문지호
Final OK by SGLee
p.228 Chapter 5.6 Exercise No.5 (Old)
Show that by using an integral.
Proof)
█
Solved by 김요섭
Revised by 배성준
Finalized by 문지호
Final OK by SGLee
p.229 Chapter 5.6 Exercise No.7(Old)
Evaluate .
Sol)
[CAS] Draw the graph.
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
Answer : █
1. Newton's method
: 1차방정식은 쉽게, 2차 방정식도 간단한 근의 공식을 이용하여 쉽게 구해내고, 3차, 4차 방정식도 복잡하지만 근의 공식을 이용하여 근을 구해낼 수 있다. 5차 이상 넘어가게 되면 공식으로 또는 간단하게 방정식의 근을 구해낼 수 없다. 5차 이상 되는 고차 방정식의 근을 구하기 위하여 뉴튼은 근의 근사값을 구하는 방법을 생각해 냈다. 그래프적으로 보면 의 그래프가 그려져 있을 때 그 그래프위의 어느 한 점
에서의 접선을 그리고 그 접선의 x절편(
)을 구하여
에서 그래프 위의 점
를 구하여 점 B에서의 접선을 그린다. 이 과정을 계속 반복하다보면
이 되는 x의 근사값을 구해낼 수 있다.
를 식으로 써서 구해보면
로 구할 수 있다.
이를 수열화 하면 공식의 틀을 갖춘 식이 나오게 된다.
이를 newton's method라 한다.
,
등을 가지고 연습해 보세요~ 계산이 복잡해 지면 sage를 쓰면 될 것입니다. 아니 어떻게 쓰는지만 알면 될 것입니다.
4. State the Procedure for Newton’s Method.
Let us consider the graph of
and we want to solve
. We start with the (proper, 해에 충분히 가까운) initial approximation
, which may be obtained by just guessing, or examining the graph of
. Then we use the tangent line
to the curve
at the point
to approximate the curve and look at the
-intercept of
, labeled
. The equation of the tangent line
is
. Thus, we obtain
. If
, we can solve this equation for
:
Under certain conditions, is usually a better approximation to the solution than
. Then we repeat this procedure with
replaced by
, using the tangent line at
. This gives a third approximation:
. Continuing this process obtains a sequence of approximations
,
,
,
as shown in the Figure. In general, if
then we have
. The number
becomes closer and closer to the solution if the sequence
converges as
. We note that if
then the sequence may not converge. In this case, we have to choose a different initial
. ■
5. State what you know about the number
:
The number
is an important mathematical constant, approximately equal to 2.71828, that is the base of the natural logarithm. This number arises in the study of compound interest, and can also be calculated as the sum of the infinite series
. The constant can be defined in many ways; for example,
is the unique real number such that the value of the derivative (slope of the tangent line) of the function
at the point
is equal to 1. The number
is defined so that when
from
as
. There is a very important exponential function that arises naturally in many places. This function is called the natural exponential function. However, for most people this is simply the exponential function. For
,
implies
, and from the general derivative above we have
. Thus the slope of a tangent line to the curve
is equal to the
-coordinate of the point. The Natural Exponential Function :
,
or
.
Since the logarithm is an increasing function, it is one-to-one and therefore has an inverse function, which we denote by exp. Thus, according to the definition of an inverse function, and
and
. In particular, we have
since
.
since
. We obtain the graph of
by reflecting the graph of
about the line
. The domain of exp is the range of the logarithm. That is,
which is the range of the logarithm, is the domain of the exponential and
, which is the domain of the logarithm is the range of exponential. If
is any rational number, then the third law of logarithms gives
. Therefore, by
. Thus,
whenever
is a rational number. This leads us to define
, even for irrational values of
, by the equation
. In other words, for the reasons given, we define
to be the inverse of the function
.
Properties of the Exponential Function. The exponential function is an increasing continuous function with domain
and range
. Thus,
for all
. Also
. So the
-axis is a horizontal asymptote of
. Exponential Function: Consider the exponential function
where
,
.
From the definition of the derivative: . Thus
. That is, the rate of change of any exponential function is proportional to the function itself. Furthurmore
because
and
if
.
is the number such that
. ■
III. (3pt x 13 = 39pt) Find or Explain or Fill the blank.
1. State the Sage command that plot the implicit function (
,
).
var(‘x, y’) f = 7*x^2 + 4*x*y + 4*y^2-23 implicit_plot(f, (x, -4, 4), (y, -4,4)) |
2. The followings explain that the equation has
at least one real root on
using Intermediate Value Theorem.
var('x') f(x)=(x)*cos(x) - sin(x) plot(f(x), x, pi, (3/2)*pi) |
print f(pi), f((3/2)*pi) |
-pi, 1 ■
Since f(x)=(x)*cos(x) - sin(x) is continuous on and
, using Intermediate Value Theorem,
there exist at least one real root of the equation on
.
find_root(f(x), pi, (3/2)*pi) |
4.493409457909064 ■
3. Find , which make
be continuous at
. [Hint: Use
]
If
is continuous at
,
.
.
Sage 명령어
■
4. We plot the graph of the derivative of (
) using Sage below.
The graph intersects the -axis at
,
,
,
.
(1) Find intervals on which is decreasing.
이 되는 구간에서 함수
가 감소하므로 위 그래프에서
가
축 아래에 위치하는 범위를 찾으면 된다.
감소구간 :
,
,
■
(여기서 끝점은 포함하지 않아도 된다. 즉, 열린구간으로 써도 된다.)
(2) Find at which
has local extreme values
가 존재하지 않거나
이 되는 critical points (임계점)의
좌우에서 도함수 의 값이
이면 극대,
이면 극소가 된다.
위의 그래프를 통해 살펴보면
극댓값을 가지는
의 값은
,
. 극솟값을 가지는
의 값은
,
이다. ■
5. . Find
[Hint: Use the definition of
,
, the properties of limits.]
(
the definition of
)
■
6. Find the limit using natural logarithm and L’Hospital’s Rule
Let
( L’Hospital’s Rule)
and
(
continuous ft.)
■
7. The tangent line at of parametric equation
is
since
.
Find the velocity (속도) and speed (속력) at .
At
, the velocity (속도) =
=
and speed (속력) =
■
8. Use differential to approximate .
Let
. Set
and
. Since
,
, we have
Hence approximately,
. ■
9. A closed cylindrical can is to hold of liquid. Find the height and radius that minimize the amount of material needed to manufacture the can.
and
Let
and
■
http://matrix.skku.ac.kr/cal-lab/cal-4-4-exs-5.html
10. If is the total value of the production when there are
workers in a plant, then the average productivity is
.
Find . Explain why the company wants to hire more worker if
?
If , then
(
)
is the rate of productivity.
(
)
This means the rate of productivity
is larger than the average productivity
which means if the company hire more workers, then they can expect to have a better productivity. ■
11. Evaluate the area covered by and
.
Consider
and
. Then the area is
Sage :
var('y') integral(y-y^2 + 2, y, -1, 2) |
Answer : 9/2 ■
12. is an anti-derivative of
. Find
. [Hint: Substitute
and
]
■
13. A honeybee population starts with 30 bees and increases at a rate of bees per week. How many honeybees are there after 10 weeks?
Since the net change in population during 10 weeks is
, the total number of honeybees after 10 weeks is
. ■
IV. (4pt x 4 = 16pt) Prove or Explain (Fill the blank).
1.
∀
> 0 [ Find
] Let
If , then
=
=
=
.
[Side calculation]
. ■
2. Show ,
and
implies
.
Proof : ■
3. If is a continuous function on
, then
is continuous on
and it is differentiable on
and
.
Proof : Let be a point in
.
By Mean Value theorem for integration, there exist in
such that
Since as
, and
is continuous.
■
4. Find .
Figure 1
Figure
The integrand suggests using
, so then
.
Now when ,
; when
,
.
Thus . ■
(QnA Participation, 4pt) Write one good example of your Note or Solution or Answer in QnA.
More than 400 problems were solved and revised and finalized in Q&A . I have made more than 4*7 contributions in it including ...
That changed my ...
(Bonus, 2pt) What you have newly learned and improved from our Honor Calculus with Sage?
Now I can draw, find and explain. And eventually I can solve most of problems in any calculus book by hand or by Sage! That was a difference.
◆ Solve-Revise-Finalize and Final OK by SGLee (only)
Solved by 문지호 Finalized by 이송섭 Refinalized by TA
P.238 Chapter 6.1 Exercise 1 (New)
Find the area of the region, bounded by the given curves.
.
Sol)
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
var('x')
f(x)=x^2-5
g(x)=22-2*x^2
P1=plot(f, x, 0, 4, color='red')
P2=plot(g, x, 0, 4)
P3=plot(g, x, 0, 3, fill=f)
show(P1+P2+P3)
integral(g-f,x,0,3)
54
Answer : 54 ■
Solved by 배성준
Finalized by 계성곤
FinalOK by SGLee
p.238 Chapter 6.1 exercise No.2(new)
Find the area of the region, bounded by the given curves.
Sol)
[CAS]Use Sage.
var('x,y')
f(x)=2
g(x)=1/cos(x)
p1=plot(f(x), (x,-4,4),color="green")
p2=plot(g(x), (x,-4,4) ,color="blue")
p3=parametric_plot((0,y),(y,-4.5,4.5),color="red")
p4=parametric_plot((pi/6,y),(y,-4.5,4.5),color="red")
p5=plot(f(x),x,0,pi/6,fill=g(x))
show(p1+p2+p3+p4+p5,aspect_ratio=1,ymax=5,ymin=-5)
show(integral(f(x)-g(x),x,0,pi/6))
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
Answer : ■
Solved by 변희성
Revised by 우시명
Finalized by 계성곤
FinalOK by SGLee
P.238 Chapter 6.1 exercise 4 (Old)
Find the area of the region, bounded by the given curves.
Sol)
(answer :
)
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
var('x,y')
f(x)=x^3
g(x)=x^5
p1=plot(f(x), (x,-1.5,1.5),color="red")
p2=plot(g(x), (x,-1.5,1.5),color="blue")
p3=plot(f(x), (x,-1,1),fill=g(x))
show(p1+p2+p3,aspect_ratio=1,ymax=1.5,ymin=-1.5)
t=integral(f(x)-g(x),x,0,1)*2
show(t)
Answer: ■
Solved by 문지호, Revised by 이송섭. Finalized by 문지호, Refinalized by TA
P.238 Chapter 6.1 Exercise 7 (Old)
Find the area of the region, bounded by the given curves.
Sol)
Two curves meet at ,
.
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
var('x')
f=x
g=x^(1/3)
P1=plot(f, x, 0, 2, color='red')
P2=plot(g, x, 0, 2)
P3=plot(g, x, 0, 1, fill=f)
show(P1+P2+P3)
integral(g-f,x,0,1)
The blue line represents , and the red line represents
Answer : █
Solved by 변희성
Revised by 우시명
Finalized by 계성곤
FinalOK by SGLee
P.238 Chapter 6.1 exercise 8 (Old)
Find the area of the region, bounded by the given curves.
Sol)
[CAS]Use sage.
var('x,y')
f(x)=4-x^2
g(x)=x^2-2
p1=plot(f(x), (x,-4,4),color="red")
p2=plot(g(x), (x,-4,4),color="blue")
p3=plot(f(x), (x,-sqrt(3),sqrt(3),fill=g(x))
show(p1+p2+p3,aspect_ratio=1,ymax=5,ymin=-4)
t=integral(f(x)-g(x),x,-3^(1/2),3^(1/2))
show(solve(f(x)==g(x),x)
show(t)
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
Answer: ■
Solved by 변희성
Revised by 우시명
Finalized by 계성곤
FinalOK by SGLee
P.238 Chapter 6.1 exercise 10 (Old)
Find the area of the region, bounded by the given curves.
Sol)
[CAS]Use sage.
var('x,y')
f(x)=x^(1/2)
g(x)=(1/3)*x
p1=plot(f(x), (x,0,10),color="red")
p2=plot(g(x), (x,-1,10) ,color="blue")
p3=plot(f(x),x,0,9,fill=g(x))
show(p1+p2+p3,aspect_ratio=1,ymax=4,ymin=-2)
show(integral(abs(f(x)-g(x)),x,0,12))
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
Answer: ■
Solved by 문지호
Revised by 계성곤
Finalize by TA
Final OK by SGLee
P. 239 Chapter 6.1 Exercise 13 (New)
Find the area of the region, bounded by the given curves.
,
Solution)
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
37/12
Answer : ■
Solved by 배성준
Finalized by 계성곤
Final OK by SGLee
p.267 Chapter 6.3 exercise No.1(new)
Find the volume generated by rotating the region bounded by the given curves about the -axis using the method of cylindrical shells.
; about the
-axis
Sol) By using Sage,
var('x,y')
p1=plot(-3/(x^2-4*x), (x,0,4),rgbcolor=(1,0,0))
p2=plot(0, (y,0,4) ,rgbcolor=(0,1,0))
show(p1+p2, aspect_ratio=1,ymax=9)
show(integral(2*x*pi*(-3/(x^2-4*x)), x, 2,3))
Answer : ■
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
Solved by 배성준
Revised by TA
Finalized by 배성준
p.267 Chapter 6.3 exercise No.5(new)
Find the volume generated by rotating the region bounded by the given curves about using the method of cylindrical shells.
; about
Sol)
As we know, .
Here, ,
Thus,
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
Answer : ■
Solved by 배성준
Finalized by 계성곤
Final OK by SGLee
p.268 Chapter 6.3 exercise No.7(new)
Find the volume generated by rotating the region bounded by the given curves about -axis using the method of cylindrical shells.
; about the
-axis
Sol) Use Sage!!
var('x,y')
f(x)=ln(x)
g(x)=0
p1=plot(f(x), (x,0,4),color="purple")
p2=plot(g(x), (x,-1,4),color="blue")
show(p1+p2, aspect_ratio=1,ymin=-4)
By
parallel translation and
-axis symmetry movement,
p3=plot(f(-x+3),(x,-1,3),color="purple")
p4=plot(g(-x+3),(x,-1,3),color="blue")
show(p3+p4, aspect_ratio=1,ymin=-1)
show(integral(2*pi*y*(3-e^y),y, 0,ln(3)))
It can be solved by other method.
show(integral(pi*(ln(-x+3))^2,(x,0,2)))
Answer : ■
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
Solve by 우시명
Revised by 이송섭
p.268 chapter 6.3 exercise 9 (Old)
Find the volume generated by rotating the region bounded by the given curves about the -axis using the method of cylindrical shells.
about the
-axis
Sol1)
Using cylindrical shells.
Answer: ■
Sol2) Use Sage.
[CAS]
var('x')
f(x)=x^2-5*x+6
g(x)=0
p1=plot(f(x),(x,0,4),rgbcolor=(1,0,0));
p2=plot(g(x),(x,0,4),rgbcolor=(0,1,0));
show(p1+p2,aspect_ratio=1)
solve(f(x)==g(x),x)
integral(2*pi*x*abs(f(x)),x,2,3)
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
Answer : ■
Solved by 우시명
Revised by 이송섭
P.281 Chapter 6.5 Exercise 8 (New)
(a) Find the average value of on the given interval.
(b) Sketch the graph of and a rectangle whose area is the same as the area under the graph of
.
Sol1)
(a)
Answer: ■
Sol2) Use sage.
[CAS]
var('x,y')
f(x)=(3*(x-4)^3)
Int = integrate(f(x),x,2,5)
print(Int)
g(x) = Int/3
p1=plot(f(x),x,2,5)
p2=plot(g(x),x,0,10, color ="red")
p3=parametric_plot((2,y),(y,-25,5),color = "green")
p4=parametric_plot((5,y),(y,-25,5),color = "green")
show(p1+p2+p3+p4)
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
(a) Answer :
(b) Rectangle made by two green lines, red line and 'x' axis ■
Solved by 이송섭 Revised by 문지호
P.282 Chapter 6.5 Exercise 12 (New)
Find the numbers such that the average value of
on the interval
is equal to
.
Sol)
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
var('x')
f=1/x
P1=plot(f, x, 1, e, fill='axis')
P2=plot(f, x, 0, 2*e, ymax=4)
P3=plot(1/(e-1), x, 1, e, fill='axis')
P4=plot(1/(e-1), x, 0, 2*e, color='red')
t1=text("$y=1/x$", (0.8, 3), fontsize=15)
t2=text("$y=1/(e-1)$", (4, 0.8), fontsize=15)
show(P1+P2+P3+P4+t1+t2)
Answer: ■
Solved by 변희성
Finallized by 우시명
Refinalized by 계성곤
Final OK by SGLee
P.293 Chapter 7.1 exercise 2 (New)
Sol)
Use integration by parts.
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
show(integral((3*x^2-2*x+1)*e^(2*x),x))
Answer : ■
solved by 변희성
Finallized by 우시명
Refinalized by 계성곤
Final OK by SGLee
P.303 Chapter 7.2 exercise 4 (New)
4.
Sol)
Use the Substitution Rule.
Let = >
=
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
show(integral(sin(x)^7*cos(x)^4,x))
Answer : ■
Solved by 변희성
Finallized by 우시명 Refinalized by 계성곤
Refinalized and Final OK by SGLee
P.312 Chapter 7.3 exercise 3 (New)
3.
Sol) Use Substitution Rule.
Let =>
[Side Calculation] [Find ]
=>
(
)
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
P.312-Chapter 7.3 exs 3 by 계성곤
show(integral(x/(16+x^2)^(1/2),x))
Answer : ■
Solved by 문지호
Revised by 이수헌
Finalized by TA
Chapter 7.4 Exercise 1(New)
Solution)
Decompose the original function to partial fraction.
==>
,
,
,
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
integral((x^2+1)/(x*(x+1)^3), x)
1/(x^2 + 2*x + 1) - log(x + 1) + log(x)
Answer : ■
Solved by 문지호
Revised by 계성곤
Finalized by TA
Final OK by SGLee
Chapter 7.4 Exercise 5(New)
Sol) Decompose the original function to partial fraction.
==>
,
,
,
,
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
A = matrix(QQ, [[1,1,0,1,0,0],[-1,1,1,0,1,0],[5,4,1,0,0,1],[-4,4,4,1,0,0],[4,0,4,0,1,1]])
A.echelon_form()
[ 1 0 0 0 0 2/15]
[ 0 1 0 0 0 2/39]
[ 0 0 1 0 0 5/39]
[ 0 0 0 1 0 -12/65]
[ 0 0 0 0 1 -3/65]
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
integral((x^2+1)/((x^3+1)*(x^2+4)),x)
Answer :
■
Solved by 이송섭 Revised by 문지호 Finalized by 이송섭
Finalized by SGLEE
P.365 Chapter 7.8 Exercise 2 (Old)
Sol)
(Integrate by parts)
. ⏨
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
(Ch-7.8-Exercise-2(old)-Solve이송섭-Revise문지호-Revise이송섭)
var('x')
g=integrate(x*e^(-x), x)
p1=plot(g(x)-g(0), x, 0, 10)
show(p1)
int=integrate(x*e^(-x), x, 0, infinity)
print(int)
1
Answer : █
Solved by 이송섭
Revised by TA
Finalized by 이송섭
Refinalized and Final OK by SGLee
P.369 Chapter 7.8 Exercise 3 (New)
Prove that is convergent.
Sol) [CAS] plot (1/(1+x^2))
(
)
1)
2)
3)
(by 1), 2), 3))
=> is converge. (By comparison theorem) ■
Note:
[CAS] show(integral(1/(1+x^2), x, -infinity, +infinity))
답은 =
.
Solved by 이송섭
Revised by 문지호
Finalized by 이송섭
Finalized by SGLEE
P.365 Chapter 7.8 Exercise 4 (New)
Sol)
□
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
(Ch-7.8-Exercise-4(new)-Solve이송섭-Revise문지호-Revise이송섭)
var('x')
p1=plot(1/(1-x), x, 0, 1)
show(p1)
int=integrate(1/(1-x), x, 0, 1)
print(int)
ValueError: Integral is divergent.
Answer : The given integral is divergent ■
Solved by 이송섭 Revised by 문지호 Finalized by 이송섭 Final ok by SGLEE
P.366 Chapter 7.8 Exercise 7 (old)
(
)
Sol1)
⏨
Sol2)
Use mathematical induction to show the following equation.
(*)
(i)Show true for
(ii) Assume true for and show true for
.
By the inductive assumption, .
By mathematical induction, (*) is true for all
is eventually true for large
. Therefore
.
⏨
Answer : ■
Solved by 이송섭
Revised by 배성준
Finalized by 우시명
Final ok SGLEE
P.365 Chapter 7.8 Exercise 7 (new)
Find .
Sol)
Take . Then,
.
⏨
Answer: ■
Solved by 이송섭
Revised by 배성준
Finallized by 우시명
Final ok SGLEE
P.365 Chapter 7.8 Exercise 9 (new)
Find .
Sol)
Let ,then
.
=1*2=2 ■
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
(Ch-7.8-Exercise-9(new)-Solve이송섭)
var('x')
f=abs((e^(-(x^2)/2))*x)
p1=plot(f,(x, -4, 4))
show(p1)
print integral(f, x, 0, infinity)
Solved by 문지호
Revised by 계성곤
Finalized and Final OK by SGLee
Chapter 7.8 Exercise 18 (Old)
Prove that the given function is divergent.
Solution)
If , then
.
=> (
)
By the comparison test, also diverges since
diverges.
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
var('x')
a=plot(1+x^2, x, 0, 3)
b=plot(1+x, x, 0, 3)
c=plot((1+x^2)/(1+x), x, 0, 3, color='red')
show(a+b+c)
Answer : By the comparison test, is divergent. ■
Solved by 이송섭 Revised by 문지호 Finallized by 우시명 Final ok by SGLEE
P.367 Chapter 7.8 Exercise 19 (New)
Sol)
Put then,
.
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
(Calculus with Sage p.367 Chapter 7.8 Problem19 이송섭, 문지호)
var('x,n')
integrate(x^(10*n-1)*e^(-x^10),x)
-1/10*(x^10)^(-n)*x^(10*n)*gamma(n, x^10)
Answer:■
Solved by 이송섭
finalized by TA
P.282 Chapter7.8 Exercise 21 (old)
Sol)
on
----------------------------------------
But ==>
, Thus you do not prove it is divergent.
-------------------------------
(wrong)
Answer: Integral is divergent. ■
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
Solved by 이송섭
Revised by TA
Finalized by 이송섭
P.365 Chapter 7.8 Exercise 28 (new)
Sol)
Let , then
.
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
ValueError: Integral is divergent
Answer: Integral is divergent. ■
Solved by 이송섭
Revised by 순샤오웨이
Finalized by 이송섭
P.369 Chapter 7.8 Exercise 34 (New)
Sol)
Let , then
.
Let .
Solved by 문지호 Revised by 이송섭
P.394 Chapter 8.3 Exercise 1 (New)
Find the center of mass of the region bounded by the cardioid (we assume that the density of the enclosed region is 1).
Sol) By the symmetry principle, the center of mass must lie on , so
. Since the given curve is
by the polar coordinate, the area of the region is computed as follows.
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
(Ch-8.3-Exercise-1-Solve문지호-Revise이송섭)
theta=var('theta');
polar_plot(sqrt((cos(theta))^2-2*(cos(theta))^3+(cos(theta))^4+(sin(theta))^2-2*(sin(theta))^3+(sin(theta))^4), (0, 2*pi), fill=True).show(aspect_ratio=1, xmin=-3, xmax=3, ymin=-3, ymax=3)
Above graph means that we can't solve this problem same way with Ch-8.3-Exercise-2.
Answer : is
■
Solved by 문지호
Revised by 배성준
Finalized by TA
P.423 Chapter 9.1 Exercise 4(New)
Determine whether the sequence converges or diverges. If it converges, find the limit.
Solution)
The denominator converges to 1, and the numerator diverges to .
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
+Infinity
Answer : █
Solved by 문지호
Revised by 배성준
Finalized by TA
P.424 Chapter 9.1 Exercise 7(New)
Determine whether the sequence converges or diverges. If it converges, find the limit.
Solution)
By the squeeze theorem .
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
0
Answer : █
Solved by 문지호
Revised by 배성준, Finalized by TA
Refinalized and Final OK by SGLee
P.424 Chapter 9.1 Exercise 9 (New)
Determine whether the sequence converges or diverges.
If it converges, find the limit.
Sol)
(by letting
)
(because e =(1+1/n)^n as n ->
infinity)
Read more: http://www.physicsforums.com
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
e^(-5)
Answer : █
Note: 그림을 그려보니 수렴한다는 것을 예측할 수 있었다. 치환하고 e =(1+1/n)^n을 이용하여 이론적으로 에 수렴함을 보였고, CAS를 이용하여 같은 값인
에 수렴함을 확인하였다. 필요시 limit((1-5/n)^n, n=+oo) 명령어를 이용하여 극한을 구할 수 있을 듯하다.
Solved by 이송섭
Revised by 문지호
Finallized by 우시명
Refinalized by TA
P.424 Chapter 9.1 Exercise 9 (New)
Find the positive integer , where
is convergent.
Sol)
Since is convergent,
1) for every positive integer
2) only if
.
Then . (
)
Answer : ■
Solved by 문지호
Revised by 이송섭
Finalized by TA
P.425 Chapter 9.1 exercise 10 (New)
Determine whether the sequence converges or diverges. If it converges, find the limit.
Sol)
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
var('x i n')
p1=plot((2/x)^(3/x), (x, 1, 20), rgbcolor=(1,0,0))
p2=list_plot([(i,(2/i)^(3/i)) for i in range(1,21,1)], rgbcolor=(0,0,1))
show(p1+p2)
limit((2/n)^(3/n), n=+oo)
1
Answer : ■
Solved by 문지호
Revised by 우시명
Finalized by 배성준
Refinialized by TA
P.425 Chapter 9.1 Exercise 11 (New)
11. Determine whether the sequence converges or diverges. If it converges, find the limit.
Sol)
Answer : The is divergent. ■
Solved by 계성곤
Revised by 문지호
Finalized by 김민수
Refinalized by TA
Final OK by SGLee
Page 444 Exercise 9.3 (New) NO.1
Test for convergence of the alternating series.
Sol)
Let .
Since is convergent, the series is convergent by Integral test.
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
-6/sqrt(x)
6
Answer : convergent ■
Solved by 계성곤
Revised by 우시명
Finalized by TA
Final OK by SGLee
Page 444 Exercise 9.3 (New) NO.2
Test for convergence of the alternating series.
Sol)
→ 2
ⅰ.
ⅱ.
By Alternating Series Test, the series is divergent.
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
Answer : divergent ■
Comment : 일반항 을
이라고 두고 앞에서부터 두 개씩 묶어보면 두 개씩 묶은 합은 무조건 양수가 됨을 알 수 있다. 이때 우리는 수열의 합을 구할 때 일반항의 극한값이 0이 되지 않으면 발산함을 알고 있으므로 발산함을 알 수 있다.
Ch-9.3-Exercise-8(old)-Solve문지호-Revised-SGLee
Solved by 문지호
Revised by SGLee
When , is the series
convergent?
Sol)
Let for all p.
(ii) for all
.
plot {{{ lnx }^2} over x }
limit_{n->infinity} {{{ ln{n} }^p} over n } = for all p.
(i) [Show the series is convergent if
]
Pf) Let
[Show ... < 0 for
]
=> (This shows eventually
.)
By Alternating Series Test, the series is convergent █
Note: Sage or 울프럼 알파 이용하여... 수렴하는 것을 관찰할 수 있습니다.
Solved by 계성곤
Revised by 우시명
Finalized by TA
Final OK by SGLee
Page 444 Exercise 9.3 (Old) NO.6
Test for convergence of the alternating series.
Sol)
Let .
By the Ratio Test, the series is absolutely convergent.
[P.440 Theorem 4. Ratio Test]
If , then the series
is absolutely convergent (and therefore convergent).
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
Answer : convergent ■
Solved by 배성준
Revised by 계성곤
Finalized by 계성곤
FinalOK by SGLee
P.453 Chapter 9.4 Exercise 1(New)
Determine the radius of convergence and interval of convergence of the following series.
Sol)
Let . Then
Using the Ratio Test, the given series is absolutely convergent
and therefore convergent when , and divergent when
.
ⅰ. ,
is divergent.
ⅱ. ,
is convergent.(
the Alternating Series Test)
Thus, the given power series converges for .
So, and
.
Answer : and
█
[Side cal] Alternating Series Test
Let
(i) for all
,
(ii)
Therefore is convergent. □
Solved by 배성준
Revised by 계성곤
Finalized by 계성곤
FinalOK by SGLee
P.453 Chapter 9.4 Exercise 2(New)
Determine the radius of convergence
and interval of convergence
of the following series.
Sol)
Let . Then
Using the Ratio Test, the given series is absolutely convergent and therefore convergent when , and divergent when
.
ⅰ. ,
is convergent.(
the Integral Test)
ⅱ. ,
is convergent.(
the Alternating Series Test)
Thus, the given power series converges for .
So, and
.
Answer : and
█
[Side cal] Alternating Series Test
Let
(i) for all
,
(ii)
Therefore is convergent by Alternating Series Test.
Let .
( convergent)
Therefore is convergent by Integral Test. □
Solved by 배성준
Revised by 계성곤
Finalized by 계성곤
FinalOK by SGLee
P.453 Chapter 9.4 Exercise 3(New)
Determine the radius of convergence and interval of convergence
of the following series.
Sol)
Let . Then
Using the Ratio Test, the given series converges for all .
So, and
.
[CAS]
var('n')
u(n)=1/factorial(2*n+1)
rho=limit(abs(u(n+1)/u(n)), n=+oo)
rho #0
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
Answer : and
█
Solved by 배성준
Revised by 계성곤
Finalized by 계성곤
FinalOK by SGLee
P.453 Chapter 9.4 Exercise 6(New)
Determine the radius of convergence and interval of convergence
of the following series.
Sol)
Let . Then
Using the Ratio Test, the given series is absolutely convergent and therefore convergent when , and divergent when
.
If , then the series becomes
. Since
for
and
, by the Comparison test,
is convergent.(
is convergent.)
If , then the series becomes
, which is converges by the Alternating Series Test.
Thus, the given power series converges for .
So, and
.
Answer : and
█
[Side cal] Alternating Series Test
Let
(i) for all
,
(ii)
Therefore is convergent. □
Solved by 배성준
Revised by 계성곤
Finalized by 계성곤
FinalOK by SGLee
P.454 Chapter 9.4 Exercise 8(New)
Determine the radius of convergence and interval of convergence
of the following series.
Sol)
Let . Then
Using the Ratio Test, the given series is absolutely convergent and therefore convergent when , and divergent when
.
ⅰ. ,
is convergent.(
the
-series Test)
ⅱ. ,
is convergent.(
the Alternating Series Test)
Thus, the given power series converges for .
So, and
. █
[Side cal] Alternating Series Test
Let
(i) for all
,
(ii)
Therefore is convergent by Alternating Series Test. □
The series converges if
and diverges if
.
is convergent. □
Solved by 배성준
Revised by 계성곤
Finalized by 계성곤
FinalOK by SGLee
P.453 Chapter 9.4 Exercise 10(New)
Determine the radius of convergence and interval of convergence
of the following series.
Sol)
Let . Then
.
Using the Ratio Test, the given series converges for .
So, and
{-2}.
Answer : and
{-2} █
Solved by 배성준
Revised by 계성곤
Finalized by 계성곤
FinalOK by SGLee
P.454 Chapter 9.4 Exercise 12(New)
Determine the interval of convergence of a power series representation for the function .
Sol)
Since this is a geometric series, it converges when . Therefore, the interval of convergence is
.
Answer : ■
Solved by 배성준
Revised by 계성곤
Finalized by 계성곤
FinalOK by SGLee
P.455 Chapter 9.4 Exercise 14(New)
Express the function as the sum of a power series by first using partial fractions. Find the interval of convergence.
Sol)
Since this is a geometric series, it converges when , and
, respectively. Therefore, the interval of convergence is
.
Answer : █
Solved by 배성준
Revised by 계성곤
Finalized by 계성곤
FinalOK by SGLee
P.455 Chapter 9.4 Exercise 15(New)
Find a power series representation for the function and determine the radius of convergence.
Sol)
The derivative of is
.
We have ,
for .
Thus,
We put in this equation to determine the value of
.
That is,
.
Thus, ,
.
Here since the radius of convergence is the same as for the original series.
Answer : ,
█
Solved by 우시명
Revised by 문지호
Finalized by TA
P.471 Chapter 9.5 Exercise 5 (New)
Obtain the Taylor series for about
.
,
Sol)
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
−15040x7+1120x5−16x3+x
Answer : ■
Comment : SAGE로 7차 항까지 구한 값이 일치하는 것을 확인할 수 있다.
Solved by 우시명
Revised by 문지호
Finalized by 계성곤
Refinalized by 계성곤
Final OK by SGLee
P.473 Chapter 9.5 exercise 15 (New)
Evaluate the limit using a series.
Sol)
[CAS]
var("x")
p1=plot(((cos(x))^2-1+x^2)/(exp(x^2)-1)^2,(x,-3,3),ymin=-0.1, ymax=0.4)
show(p1)
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
Change and
to polynomial.
=
=
Answer : ■
NOTE : Sage를 이용하여 그래프의 개형을 파악하고 대략적인 값을 예측한 뒤 직접 계산하여 다시 확인하였다.Solved by 우시명
Revised by 문지호
P.474 Chapter 9.5 exercise 21 (New)
Evaluate using the binomial series where
.
Sol) For ,
.
Since =
,
.
[CAS]
http://www.wolframalpha.com/input/?i=d%5E8%7B%281%2B3*x%5E2%29%5E%28-1%2F3%29%7D%2Fdx%5E8%2C+x%3D0
Answer : 470400 ■
Solved by 이송섭
Revised by 문지호
Finalized by 계성곤
Final OK by SGLee
P.365 Chapter 10.1 Exercise1 (New)
(a) Find the Cartesian equation of the curve.
(b) Sketch the curve and indicate with an arrow the direction in which the curve is traced as the parameter increases.
Sol)
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
var('t,x,y')
x=cos(t)*(1+cos(t))
y=sin(t)*(1+cos(t))
a=0
b=2*pi
p=parametric_plot((x, y), (t, a, b))
small=0.001
step=pi/16
n=(b-a)/step
arr=sum([arrow((x(t=a+i*step),y(t=a+i*step)),(x(t=a+i*step+small), y(t=a+i*step+small)))for i in range(1, n) ])
p+arr
Answer : (a)
(b) [the above graph] ■
NOTE : http://matrix.skku.ac.kr/cal-lab/sage-grapher-para.html에서 t의 변화에 따른 그래프의 변화를 애니메이션으로 볼 수 있었다.
solved by 문지호
Page 485 Exercise 10.1 (New) NO.5
(a) Find the Cartesian equation of the curve.
(b) Sketch the curve and indicate with and arrow the direction in which the curve is traced as the parameter increases.
,
Sol)
(a)
Since
,
.
The given curve is hyperbola whose focus points are .
Since , domain of the function is
.
(b)
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
var('t,x,y')
x=3*cosh(t)
y=4*sinh(t)
a=-5
b=5
p=parametric_plot((x,y),(t,a,b))
small=0.001
step=0.25
n=(b-a)/step
arr=sum([arrow((x(t=a+i*step), y(t=a+i*step)),(x(t=a+i*step+small),y(t=a+i*step+small))) for i in range(1,n) ])
p+arr
Answer : (a) █
Solved by 이송섭 Revised by 배성준 Finalized by TA
Page 486 Exercise 10.1 (new) NO.8
(a) Find the Cartesian equation of the curve.
(b) Sketch the curve and indicate with an arrow the direction in which the curve is traced as the parameter increases.
Sol)
(a)
=> =>
(b)
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
var('t,x,y')
x=(-2/3)*e^(-t) + (22/6)*e^(2*t)
y=(-4/3)*e^(-t) + (11/6)*e^(2*t)
a=0; b=3
p=parametric_plot((x, y) , (t, a, b))
small=0.001; step=0.25
n=(b-a)/step
arr=sum([arrow((x(t=a+i*step), y(t=a+i*step)), (x(t=a+i*step+small), y(t=a+i*step+small))) for i in range(1,n) ])
p+arr
■
Solved by 이송섭
Revised by 배성준
Finalized by TA
Page 489 Exercise 10.1 (old) NO.9
Find a parametric equation for the path of a particle that moves along in the manner described below.
(a) Once around clockwise, starting at (3, 1).
(b) Twice around counterclockwise, starting at (3, 1).
(c) Halfway around counterclockwise, starting at (1, 3).
(d) Graph the semicircle traced by the particle.
Sol)
(a) Parametric equation of is
. This equation start at
when
.
So .
(b) Because counter clockwise, convert in (a) to
.
(c) At
(d)
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
■
Solved by 이송섭
Revised by 배성준
Finalized by 문지호
Finalized by TA
Page 487 Exercise 10.1 (new) NO.11
Find general sets of parametric equations to represent the curve .
Sol)
Let . Then we consider whether
is well defined in
.
(1)
|
|
|
|
0 |
|
|
0 |
|
(2)
|
|
|
|
|
|
|
|
|
(3)
|
|
|
|
|
|
|
|
|
Thus, choose and
in each case when
. ■
Solved by 이송섭
Revised by 배성준
Finalized by 문지호
Final OK by SGLee
Page 487 Exercise 10.1 (New) NO.11
Find general sets of parametric equations to represent the curve .
Sol 1)
Let , then
.
So, .
i) and
is integer except 0.
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
ii) and
are rational number except integer.
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
iii) One of and
is irrational number or
and
are irrational number.
Case by case.
Sol 2)
Let , then
.
can be any surjection onto
.
Answer : Follow the solution. █
solved by 문지호
Page 485 Exercise 10.1 (Old) NO.13
Investigate the family of curves defined by the parametric equations
,
.
How does the shape change as c changes? In particular, you should identify values of for which the basic shape of the curve chages.
Sol)
http://matrix.skku.ac.kr/cal-lab/cal-9-1-13.html
t=var('t')
@interact
def _(c=(0,2)):
p=parametric_plot((sin(t)*(c-sin(t)),cos(t)*(c-sin(t))),(t,0,2*pi))
show(p,xmin=-3,xmax=2,ymin=-2,ymax=2)
c = 1
Answer : Shape changes between ,
,
. █
Solved by 계성곤
Revised by 김민수
Finalized by 배성준
Refinalized by 계성곤
FinalOK by SGLee
Page 510 Exercise 10.3 (New) NO.3
Plot the point whose polar coordinates are given. Then, find the Cartesian coordinates of the point.
Sol)
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
def Polar(r,theta):
#converts Polar to Cartesian Coordinates
CartC = ([r*cos(theta),r*sin(theta)]);
return CartC;
pt=Polar(8,13/3*pi);
show( vector(pt))
list_plot([pt], aspect_ratio=1,xmin=3, xmax=8, ymin=3, ymax=8)
Answer : ■
Solved by 계성곤
Revised by 김민수
Revised by 배성준
Finalized by 계성곤
FinalOK by SGLee
Page 510 Exercise 10.3 (New) NO.6
The Cartesian coordinates are given. Find two other pairs of polar coordinates of the point, one with and other.
Sol)
,
, and
Since (,-
) is in the second quadrant, the polar coordinates are
as
,
as
Answer : ■
Solved by 계성곤
Finalized by 김민수
Refinalized by 배성준
Refinalized by 계성곤
FinalOK by SGLee
Page 511 Exercise 10.3 (Old) NO.9
Find a formula for the distance between the points with polar coordinates and
.
Sol)
Answer : ■
Solved by 계성곤
Revised by 김민수
Revised by 배성준
Finalized by 계성곤
FinalOK by SGLee
Page 511 Exercise 10.3 (New) NO.12
Find a polar equation for the curve represented by the given Cartesian equation.
Sol)
Answer : ■
Solved by 계성곤
Revised by 김민수
Finalized by 배성준
Refinalized by 계성곤
FinalOK by SGLee
Page 511 Exercise 10.3 (New) NO.15
Find a Cartesian equation for the curve represented by the given polar equation.
Sol)
Answer : ■
Solved by 계성곤
Revised by 김민수
Finalized by 배성준
Refinalized by 계성곤
FinalOK by SGLee
Page 511 Exercise 10.3 (Old) NO.18
Sketch the curve with the given polar equation.
Sol)
[CAS]
r=var('r');
polar_plot(3,(0, 2*pi)).show(aspect_ratio=1, xmin=-5, xmax=5, ymin=-5, ymax=5)
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
Answer :
■
Solved by 계성곤
Finalized by 김민수
Refinalized by 계성곤
FinalOK by SGLee
Page 511 Exercise 10.3 (New) NO.21
Sketch the curve with the given polar equation.
Sol)
[CAS]
theta=var('theta');
polar_plot(sin(theta)+(sin(theta))^2+exp(theta), (0, 20*pi)).show(aspect_ratio=1, xmin=-70, xmax=100, ymin=-170, ymax=20)
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
Answer :
■
Solved by 계성곤
Revised by 배성준
Finalized by 계성곤
FinalOK by SGLee
Page 513 Exercise 10.3 (New) NO.24
Sketch the curve with the given polar equation.
Sol)
[CAS]
theta=var('theta');
p1=polar_plot(sqrt(cos(2*theta)), (0, 1/4*pi))
p2=polar_plot(sqrt(cos(2*theta)), (3/4*pi,pi))
p3=polar_plot(sqrt(cos(2*theta)), (pi,5/4*pi))
p4=polar_plot(sqrt(cos(2*theta)), (7/4*pi, 8/4*pi))
show(p1+p2+p3+p4, aspect_ratio=1, xmin=-1, xmax=1, ymin=-0.5, ymax=0.5)
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
Answer :
■
Solved by 계성곤
Revised by 김민수
Finalized by 계성곤
Final OK by SGLee
Page 513 Exercise 10.3 (Old) NO.27
Show that the curve (also a conchoid) has the line
as a horizontal asymptote by showing that
. Use this fact to help sketch conchoid.
Sol)
ⅰ) as
or
ⅱ) as
or
is a horizontal asymptote.
[CAS]
theta=var('theta');
polar_plot(2-csc(theta), (0, 2*pi)).show(aspect_ratio=1, xmin=-15, xmax=15, ymin=-5, ymax=5)
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
Answer : is a horizontal asymptote. ■
Solved by 계성곤
Revised by 배성준
Finalized by 계성곤
FinalOK by SGLee
Page 514 Exercise 10.3 (New) NO.30
Find the slope of the tangent line at the given point.
,
Sol)
[CAS]
theta=var('theta');
polar_plot((cos(theta))^2-1, (0, 2*pi)).show(aspect_ratio=1, xmin=-1, xmax=1, ymin=-1.5, ymax=1.5)
Answer : 0 ■
NOTE : Sage를 이용하여 먼저 그래프의 개형을 확인하고 기울기를 예상했다. 그리고 다시 직접 계산하여 비교해보았다.
solved by 배성준
Final OK by SGLee
Page 522 Exercise 10.4 (New) NO.1
Find the area of the region that is bounded by the given curve and lies in the specified sector.
,
Sol)
Use Sage. http://math1.skku.ac.kr/home/pub/2279 (배성준)
var('theta')
polar_plot(theta^2-theta, (0, pi/2), fill=true).show(aspect_ratio=1, xmin=-1/2, xmax=1/2, ymin=-1/2, ymax=1)
r=theta^2-theta
A=integral(1/2*r^2,theta, 0, pi/2)
show(A)
Answer : █
Solved by 배성준
Revised by 우시명
Finalized by 배성준
Final OK by SGLee
Page 522 Exercise 10.4 (New) NO.3
Find the area of the region that is bounded by the given curve and lies in the specified sector.
,
Sol)
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
http://math1.skku.ac.kr/home/pub/2280
var('theta')
polar_plot((3*theta)^(1/2)+2, (0, pi*2/3), fill=true).show(aspect_ratio=1, xmin=-3, xmax=3, ymin=-1, ymax=5)
r=(3*theta)^(1/2)+2
A=integral(1/2*r^2,theta, 0, pi*2/3)
show(A)
Answer : █
Solved by 배성준
Final OK by SGLee
Page 522 Exercise 10.4 (New) NO.5
Find the area bounded by one loop of the given curve.
Sol)
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
var('theta')
polar_plot(2*sin(2*theta), (0, 2*pi), fill=true).show(aspect_ratio=1, xmin=-3, xmax=3, ymin=-3, ymax=3)
r=2*sin(2*theta)
A=integral(1/2*r^2,theta, 0, 2*pi)
show(A)
Answer : █
Solved by 우시명
Finalized by 배성준
Final OK by SGLee
P.542 Chapter 10.5 exercise 1 (New)
Sketch the parabola with the given equation. Show and label its vertex, focus, axis, and directrix.
Sol) Draw the graph by using sage, and find the values asked.
Vertex : (6, 3), focus : (6, 4), axis : x=6, directrix : y=2 [CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
var('x, y')
AA=implicit_plot((x-6)^2==4*(y-3), (x, -6, 16), (y, -2, 10))
f1=point((6,4), pointsize=20, color='blue')
A=implicit_plot(x==6, (x, -5, 14), (y, -1, 9))
B=implicit_plot(y==2, (x, -5, 14), (y, -1, 9))
v1=point((6, 3), pointsize=20, color='red')
show (AA+f1+A+B+v1)
■
Solved by 변희성
Revised by 배성준
Finallized by 우시명
P.542 Chapter 10.5 exercise 2 (New)
Sketch the parabola with the given equation. Show and label its vertex, focus, axis, and directrix.
Sol)
Use sage.
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
var('x, y')
implicit_plot(3*y+x^2+2*x==0, (x, -10, 10), (y, -5, 5))
Vertex : (-1, ), focus : (-1,
), axis : x=
, directrix : y=
■
Solved by 우시명
Finalized by 배성준
Final OK by SGLee
P.542 Chapter 10.5 exercise 5 (New)
Find the vertices and foci of the ellipse and sketch its graph.
Sol) Using sage and follow rule about ellipse.
답: foci : =>
vertices :
[그래프]
□
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
var('x, y')
ellipse=implicit_plot(x^2/7 + y^2/3 == 1, (x, -3, 3), (y, -3, 3))
f1=point((2,0), pointsize=20, color='blue')
f2=point((-2,0), pointsize=20, color='blue')
v1=point((sqrt(7),0), pointsize=20, color='red')
v2=point((-sqrt(7),0), pointsize=20, color='red')
v3=point((0,sqrt(3)), pointsize=20, color='red')
v4=point((0,-sqrt(3)), pointsize=20, color='red')
show(ellipse+f1+f2+v1+v2+v3+v4) ■
Solved by 변희성
Revised by 배성준
Finallized by 우시명
P.543 Chapter 10.5 exercise 7 (Old)
Find the vertices and foci of the ellipse and sketch its graph.
Sol)
focus(f)
vertix(v) ■
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
[CAS]
var('x, y')
ellipse=implicit_plot(9*x^2+4*y^2-32*y+28==0,(x,-3,3),(y,0,8))
f1=point((0,4-sqrt(5)), pointsize=20, color='red')
f2=point((0,4+sqrt(5)), pointsize=20, color='red')
v1=point((2,4), pointsize=20, color='red')
v2=point((-2,4), pointsize=20, color='red')
v3=point((0,7), pointsize=20, color='red')
v4=point((0,1), pointsize=20, color='red')
show(ellipse+f1+f2+v1+v2+v3+v4)
Solved by 변희성
Revised by 배성준
Finallized by 우시명
P.544 Chapter 10.5 exercise 10 (New)
Find the vertices, foci, and asymptotes of the hyperbola and sketch its graph.
Sol)
Use sage.
focus(f)
vertix(v) ■
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
[CAS]
x,y=var('x, y')
hyperbola=implicit_plot(y^2/9-x^2/16==1,(x,-5,5),(y,-8,8))
f1=point((0,-5), pointsize=20, color='red')
f2=point((0,5), pointsize=20, color='red')
v1=point((0,3), pointsize=20, color='red')
v2=point((0,-3), pointsize=20, color='red')
show(hyperbola+f1+f2+v1+v2)
Solved by 변희성
Finallized by 우시명
P.544 Chapter 10.5 exercise 12 (New)
Identify the type of conic section whose equation is given and find the vertices and foci.
Sol)
(0,2)
vertices: (,2)(
,2)(0,4)(0,0)
focus: (0,2+)(0,2
) ■
[CAS]
var('x,y')
ellipse=implicit_plot(x^2/2+(y-2)^2/4==1,(x,-2,2),(y,-2,8))
f1=point((0,2-sqrt(2)), pointsize=20, rgbcolor=(1,0,0));
f2=point((0,2+sqrt(2)), pointsize=20, rgbcolor=(1,0,0));
v1=point((-sqrt(2),2), pointsize=20, rgbcolor=(0,0,1));
v2=point((sqrt(2),2), pointsize=20, rgbcolor=(0,0,1));
v3=point((0,0),pointsize=20,rgbcolor=(0,0,1));
v4=point((0,4),pointsize=20,rgbcolor=(0,0,1));
show(ellipse+f1+f2+v1+v2+v3+v4,aspect_ratio=1, xmin=-2, xmax=2, ymin=-1, ymax=5)
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
Solved by 변희성
Finallized by 우시명
P.545 Chapter 10.5 exercise 15 (New)
Find an equation for the conic that satisfies the given conditions.
Parabola, vertex (3,5), focus (3,9)
Sol)
■
[CAS]
var('x,y')
implicit_plot((x-3)^2-16*y,(x,-10,15),(y,-10,10))
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
Solved by 변희성
Finallized by 우시명
P.546 Chapter 10.5 exercise 21 (New)
Find an equation for the conic that satisfies the given conditions.
Hyperbola, foci (,0) asymptotes
Sol)
a=5, b=12, c=13
■
[CAS] http://sage.skku.edu/ 또는 https://sagecell.sagemath.org/
[CAS]
var('x,y')
implicit_plot(x^2/144-y^2/25-1,(x,-20,20),(y,-10,10))
[Calculus 1 Sample Mid term Exam]
I. ( 2pt x 12 = 24) Mark True(T) or False(F) in the blank ( ).
1. ( F ) If and
exist, then
also exists. (Conterexample : 0/0)
2. ( T ) If has a local minimum (or maximum) at
and
exists, then
.
3. ( T ) Let be continuous on
. Suppose
and
, then there exists a number
in
such that
.