(a)[3]
Simplify the fraction $\frac{x^2 - 25}{x^2 - x - 20}$.
(b)[3]
Write this as a single fraction in its simplest form: $\frac{x+5}{x} + \frac{x+8}{x-1}$.
(c(i))[2]
Find $\frac{dy}{dx}$, the derivative of $y$.
(c(ii))[2]
Calculate the gradient of the curve $y = 2x^3 - 4x^2 + 6$ when $x = 4$.
(c(iii))[4]
Find the coordinates of the two stationary points on this curve.