Question

Could someone help me with this critical numbers problem?

Answer 1

do you know how to compute a derivative?

Answer 2

it would be 4t^4-16t right?

Answer 3

nope. typo error maybe?

Answer 4

Sorry, I meant 4t^3-16t

Answer 5

good. now find the roots of that expression 4t^3 -16t

Answer 6

-2, 0, 2?

Answer 7

right. those are your critical numbers.
now find the 2nd derivative

Answer 8

4 (-4+3 t^2)

Answer 9

find the roots.

Answer 10

2/(sqrt3) and -2/(sqrt3)

Answer 11

okay. there are five critical numbers. find the sign of the first and second derivatives in each interval defined by those critical numbers.

Answer 12

Oh, alright. Thanks