Differentitate:X^2.sinx/(x+1)(x^2-1)......???

y = (x^2 sinx) / (x+2)(x^2-1)

= (x^2 sinx)/(x^3+2x^2-x-2)
Woah ... this will get messy
d/dx (x^2 sinx) = 2x sinx + x^2 cosx
d/dx (x+2)(x^2-1) = 3x^2+4x-1

y' =
(2x sinx + x^2 cosx)(x^3+2x^2-x-2) - (x^2 sinx)(3x^2+4x-1)
-------------------------------------------------------------
(x^3+2x^2-x-2)^2

Wolframalpha.com renders that as what you see when you scroll down at

http://www.wolframalpha.com/input/?i=%28x^2+sinx%29+%2F+%28%28x%2B2%29%28x^2-1%29%29