Here's the question you clicked on:
Idealist
Find all open intervals on which f(x)=x/(x^2+x-2) is decreasing. I found that f'(x)=-(x^2+2)/(x^2+x-2)^2 but what do I do after that?
So when a function is decreasing it's derivitive is negative, so you simply set the inequality \[\frac{ -(x ^{2}+2) }{ (x ^{2}+x-2)^{2} } < 0\]
So is the answer (negative infinity, -2)U(-2, 1)U(1, infinity)?