critical numbers

physics_ash82

Im supposed to find the critical numbers for the function:
F(x)= x^3-12x^2
I think I did it right I just needed some reassurance, I got
F'(x)= 3x^2-24
=3x(x-8)
=3x=0 and x-8=0

so the critcal numbers are x=0 and x=8 I think I hope someone can tell me if I did this right

Thanks
ash

benorin

yes, correct [save typo F'(x)= 3x^2-24x = 3x(x-8)]

physics_ash82

Thank you I might need more help later