Question

How many criticals in x^(4/5) (x-4)^2

Answer 1

Have you considered the 1st Derivative?

Answer 2

i know the answer is 3..but dont know why

Answer 3

criticals are where the first derivative is 0 or does not exist within a given domain. I recognize this problem from the stewart textbook hah

Answer 4

Well then, what do you get for the 1st Derivative?

Answer 5

if y=x^(4/5) (x-4)^2
what is dy/dx ?
then set up dy/dx=0
solve for x=? thats your critical poits

Answer 6

A plot is attached. The red curve is the derivative of the blue.