First step to finding the derivative of 20x/(x^2-4)^2

[Cafe au lait]

I got f'(x)=[(x^2-4)^2(20)-2(x^2-4)(2x)(20x)]/(x^2-4)^4
=(-80x^4+340x^2-80)/(x^2-4)^3
and simplify

But I am pretty sure my first step was wrong, like I did the chain or product rule wrong because my answer does not match up to what my TI-89 says it is supposed to be.

 

[tkhunny]

Why would you use chain and product when theer is a perfectly good quotient rule hanging around. In any case, that step came out just fine. If you made an error, it was in subsequent algebra.