Mathematics 9709 · AS & A Level · Differentiation

Differentiation — practice question

The curve is defined by $xy + y^2 e^{-x} = 4$.
(a)[4]

Show that the result is $\displaystyle \frac{dy}{dx} = \frac{y^2 - y e^x}{x e^x + 2y}$.

(b)[2]

Find the gradients of the tangents to the curve at $x = 0$.

Worked solution & mark scheme

This 6-mark question has a full step-by-step worked solution and mark scheme. One marking point: Using the product rule, differentiating $xy$ gives $y+x\frac{dy}{dx}$

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