(a)[3]
If $2x = \tan y$, prove that $\frac{dy}{dx} = \frac{2}{1 + 4x^2}$.
(b)[7]
Hence determine the exact value of $\int_{\frac{1}{2}}^{\frac{\sqrt{3}}{2}} x\tan^{-1}(2x)\,dx$.
Mathematics 9709 · AS & A Level · Integration
If $2x = \tan y$, prove that $\frac{dy}{dx} = \frac{2}{1 + 4x^2}$.
Hence determine the exact value of $\int_{\frac{1}{2}}^{\frac{\sqrt{3}}{2}} x\tan^{-1}(2x)\,dx$.
This 10-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Arrive at $2=\sec^2y\frac{dy}{dx}$, or a correct equivalent” …