Mathematics 9709 · AS & A Level · Differentiation

Differentiation — practice question

The curve is given by the equation $\ln(xy) - y^3 = 1$.
(i)[4]

Demonstrate that $\frac{dy}{dx} = \frac{y}{x(3y^3 - 1)}$.

(ii)[4]

Determine the coordinates of the point at which the tangent to the curve is parallel to the $y$-axis, with each coordinate correct to $3$ significant figures.

Worked solution & mark scheme

This 8-mark question has a full step-by-step worked solution and mark scheme. One marking point: Give or indicate $\frac{1}{x}+\frac{1}{y}\frac{dy}{dx}$ as the derivative of $\ln(xy)$

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