Question

check my math please. y=x^5-4x^4+4x^3
use 2nd derivative test

Answer 1

i just want to find the critical points of the second derivative test

Answer 2

i got this (6+-sqrt(3))/5 can someone check my math please? thanks

Answer 3

f ''(x) would be 20x^3-48x^2+24x if im correct

Answer 4

the second derivative is a cubic polynomial
how did you find the roots of it?

Answer 5

oh i see

Answer 6

then it has 3 roots all together i guess

Answer 7

i guess those two and also 0

Answer 8

looks good to me
http://www.wolframalpha.com/input/?i=20x^3-48x^2%2B24x

Answer 9

can i ask you something else