CAPE Pure Mathematics Unit 1 · May/June 2012 · Paper 1 · Question Q31

The first derivative of \frac{-1}{x^2 - 1} with respects to x is

1. (A)\frac{-2x}{(x^2 - 1)^2}
2. (B)\frac{2x}{(x^2 - 1)^2}
3. (C)\frac{x}{2(x^2 - 1)}
4. (D)\frac{-x}{2(x^2 - 1)}