The function has rule $f(x) = \frac{4}{x^3} - \frac{3}{x} + 2$ for $x \neq 0$. Its graph, $y = f(x)$, is displayed in the diagram.
(a)[5]
Find the set of values of $x$ for which $f(x)$ is decreasing.
(b)[8]
A triangle is formed by the $y$-axis, the normal to the curve at the point where $x = 1$ and the tangent to the curve at the point where $x = -1$. Find the area of the triangle. Give your answer correct to 3 significant figures.
Worked solution & mark scheme
This 13-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Derivative correctly given as $\frac{dy}{dx}=\frac{12}{x^4}+\frac{3}{x^2}$” …