Calculus critical numbers help

the function f(x) = 8x^3 - 24x + 3 has two critical numbers.

the smaller one = ?
the larger one = ?

to find the critical numbers you just take the derivative of the function, then find the "zeros"

so the derivative of this function is

= 24x^2 - 24
= 24(x^2 -1)
= 24(x+1)(x-1)

critical numbers = -1,0,1

Differentiate the function with respect to x:
f'(x) = 24x^2 - 24

When f'(x) = 0

24(x^2 -1) = 0
==> x = 1 or x=-1

Matey before me didn't do the last part HA!!!!

you need to plug your values of x into the f(x)

when x = 1, f(x) = 8 -24 +3 = -13
when x = -1, f(x) = -8+24+3 = 19