Question

Find the value of a so that x=1is a critical number for f(x)=x^3+2ax^2+5x+1

Answer 1

a)-2
b)-1
c)0
d)1
e)2

Answer 2

you have the derivative?

Answer 3

Is it \[3x ^{2}+4ax+5\]?

Answer 4

yes..

Answer 5

now. for x=1 to be a crit #, f'(1) = 0. so you'll need to solve
0 = 3*(1)^2 + 4a*(1) + 5

Answer 6

need more help?

Answer 7

Woah, I think I just did something wrong. I was supposed to solve for a right? Well I got -3.5.

Answer 8

let's see