Question

f(x)=−3+8x−x^3

(A) Use interval notation to indicate where f(x) is increasing.
Note: Use 'INF' for , '-INF' for −, and use 'U' for the union symbol.
Increasing:
(B) Use interval notation to indicate where f(x) is decreasing.
Decreasing:

(C) List the x values of all local maxima of f. If there are no local maxima, enter 'NONE'.
x values of local maximums =

(D) List the x values of all local minima of f. If there are no local minima, enter 'NONE'.
x values of local minimums =

Answer 1

has u find the derivative?

Answer 2

yeah i did but i dont know what to do from there

Answer 3

and the critical points?

Answer 4

yeah im not sure if they are right but i got sqrt 8/3 and -sqrt8/3

Answer 5

mmmm let me check

Answer 6

give me 2 min

Answer 7

sqrt(8/9) ?

Answer 8

yeah and i took the sqrt of the bottom

Answer 9

mmm i understand yes the critical points r right

Answer 10

so from there what do i do

Answer 11

well u have some intervals now

Answer 12

do u know whic intervals?

Answer 13

no im not really sure

Answer 14

ok u have the critical points that points give u some intervals
that is (-INF, -sqrt(8/9) (-sqrt(8/9), sqrt(8/9)) (sqrt(8/9) , INF)

Answer 15

3 intervals given by the critical points

Answer 16

im still a bit confuse on how im suppose to know which is a max and which is a min

Answer 17

well the critical points must be the max and the min

Answer 18

do u got that?

Answer 19

yeah i think so lol

Answer 20

ok but u must determine if a critical point is a max or a min