Calculus-Sec-4-2-Solution
4.2 The Shape of a Graph by SGLee - HSKim - JHLee
1-5. 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 .
1. .
http://matrix.skku.ac.kr/cal-lab/cal-4-2-1.html
(a) local maximum:
local minimum:
(b) increasing on
decreasing on
(c) inflection point at
concave down on
concave up on
2.
http://matrix.skku.ac.kr/cal-lab/cal-4-2-2.html
(a) local minimum:
(b) increasing on
decreasing on
(c) inflection point at
concave down on
concave up on
3. .
(a) local maximum:
local minimum:
(b) increasing on
decreasing on
(c) inflection point at
concave down on
concave up on
To find local maximum and minimum, use the next sage code.
To find inflection points, we calculate the second derivative.
4.
(a) local maximum : No
local minimum :
(b) increasing on
decreasing on
(c) inflection point : No
concave up on
5.
http://matrix.skku.ac.kr/cal-lab/cal-4-2-5.html
(a) Maximum : 1, Minimum : 0
(b) interval of increase :
interval of decrease :
(c) inflection point at 변곡점은 0.722, -0.722
concave down on
6-11. Find the inflection points of In addition, find intervals in which the graph of is concave upward or concave downward.
6.
(a) inflection point at
(b) concave down on
concave up on
7.
(a) inflection point at
(b) concave up on
concave down on
8. ,
(a) inflection point at
(b) concave down on
concave up on
9.
http://matrix.skku.ac.kr/cal-lab/cal-4-2-9.html
(a) critical point at , inflection point at
(b) concave down on
concave up on .
10.
(a) inflection point at
(b) concave up on
concave down on
11.
(a) inflection points : and
(b) concave down on
concave up on
12-15. Find the vertical and horizontal asymptotes of .
12.
vertical asymptote
horizontal asymptote
14.
horizontal asymptote
16-18. Sketch the graph of using the following information.
(a) Find the local maximum and minimum values of .
(b) Find the intervals of increase or decrease.
(c) Find the inflection points of and intervals of concavity.
(d) Find the vertical and horizontal asymptotes.
16.
(a) local maximum : No
local minimum : No
(b) decreasing on
(c) inflection point at
concave up on
concave down on
(d) vertical asymptote :
horizontal asymptote :
17.
,
(a) local minimum at
(b) increasing on
decreasing on
(c) inflection point : No
concave up on
(d) vertical asymptote:
horizontal asymptote: No
18. ,
and
and ; and
(a) local minimum at
local maximum :
(b) increasing on
decreasing on
(c) inflection point at
concave up on
concave down on
(d) vertical asymptote: No
horizontal asymptote:
19. Find all the values of a such has different roots.
Let . Then will have one local maximum and one local minimum. There will be roots if and only if the maximum is positive and the minimum is negative.
and .
Note that and . Hence has local maximum at and local minimum at . Therefore, if there will be roots.
20. Find the minimum constant for which for all real .
http://math1.skku.ac.kr/home/pub/1040/
,
local minimum at
Therefore, .
21. Find so that has two inflection points at and .
and so ,
and so .
22. Let .
(a) Find and .
(b) Find the vertical and horizontal asymptotes of .
(c) Sketch the graph of using (a) and (b).
(a)
(b) ,
vertical asymptote
horizontal asymptote
(c)
|
|
|
|
|
|
||
23. Let and be increasing functions. Prove that is increasing function.
For , ,
Therefore, is increasing.
24. Prove the Concavity Test.
(a) By Increasing Test
If on an interval then is increasing on .
So is concave upward on .
Part (b) is proved similarly.
26. Let . Find the local maximum, minimum values and inflection points of . Sketch the graph of .
http://matrix.skku.ac.kr/cal-lab/cal-4-2-26.html
local maximum :
local minimum : No
inflection point :
27. Let . Find the local maximum, minimum values and inflection points of .
http://matrix.skku.ac.kr/cal-lab/cal-4-2-27.html
local maximum :
local minimum : No
inflection point :