how does the derivative of
-1/ (x - 1)^2
=
2/ (x - 1)^3
seems simple..but i get x in the numerator
$\displaystyle u = -1 \: \rightarrow \: u' = 0$
$\displaystyle v = (x-1)^2 \: \rightarrow \: v' = 2(x-1)$
Quotient Rule $\displaystyle y' = \frac{u'v - v'u}{v^2}$
In this case we can get rid of $\displaystyle u'v$ because it equals 0.
$\displaystyle y' = -\frac{v'u}{v^2}$. Remember your signs and factors