Question

solve this to get find global extreme values:
f(x)=x^4-8x^2+4x+2 at [-(20/25),(64/25)]

Answer 1

Why do you specify a point?

Answer 2

is that range?

Answer 3

yep!! extrema values fall in the range so it is specified.

Answer 4

can't solve the cubic is all?

Answer 5

find criticle points

check criticle points and boundary points

Answer 6

i know that but i couldn't solve the equation

Answer 7

D[x^4-8x^2+4x+2 ]-->= 4x^3 -16x+4=0

Answer 8

http://www.wolframalpha.com/input/?i=4x%5E3%20-16x%2B4%3D0&t=crmtb01

Answer 9

and how to solve that eqn to get value of x

Answer 10

x^3-4x+1=0...then..
main problem is , to solve for x...

Answer 11

@sam yes