(i)[5]
Show that the result is $\frac{dy}{dx} = \cot t$.
(ii)[2]
Hence find the $x$-coordinate of the point on the curve where the gradient is equal to $2$. Give your answer correct to 3 significant figures.
Mathematics 9709 · AS & A Level · Differentiation
Differentiation — practice question
The curve is described parametrically by $x = t - \tan t$ and $y = \ln(\cos t)$, with $-\frac{1}{2}\pi < t < \frac{1}{2}\pi$.
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