Find the intervals on which f(x) is increasing and decreasing using the, given, first derivative.
f'(x)=(-2x)/(x^2-4)^2

Question

Find the intervals on which f(x) is increasing and decreasing using the, given, first derivative. 
f'(x)=(-2x)/(x^2-4)^2

anonymous · Answer

$$f'(x)=\frac{ -2x }{ (x^2-4)^2}$$

anonymous · Answer

evidently the denominator is always positive (unless it is zero, where the function is undefined) 
so the only question is, for which $x$ is $-2x>0$ and that would be if $x<0$

anonymous · Answer

oh, that answer was for "increasing" so increasing if $x<0$ decreasing if $x>0$ and obviously undefined at $x=2, x=-2$