Is this correct? I'm supposed to find the critical numbers: g(x)=(x^2+2x-15)/(x^2+2x-3) where the first derivative equals g'(x)=24(x+1)/(x+3)^2(x-1)^2 .... I made x equal to zero and solved for x and got critical numbers -1, -3, 1 but -3 and 1 were undefined... so the only critical number would be -1 right?

Question

zzr0ck3r · Answer

looks right, if you did you derivatives right.

anonymous · Answer

If derivative is undefined for some x, it is also a critical number ! :)

anonymous · Answer

so -3 and 1 are also critical numbers?

zzr0ck3r · Answer

critical numbers have 0 slope, not infinite

zzr0ck3r · Answer

maybe im wrong

anonymous · Answer

I read that Critical numbers are points where
1.F(x) is undefined
2.F'(x) is zero
3.F'(x) is undefined

zzr0ck3r · Answer

sounds like he knows what hes talking about^^^

anonymous · Answer

... because i'm also supposed to find the intervals of increase and decrease and I thought that it wasn't a critical number if it was undefined.

anonymous · Answer

so I made a graph and found where it increases and decreases with only the critical number -1 |dw:1370934846827:dw|