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\includegraphics[max width=\textwidth, alt={}, center]{f85c4010-17b1-441c-ae8a-e77573d1b0c3-3_423_837_1352_651}
The diagram shows the curve with parametric equations
$$x = 2 - \cos t , \quad y = 1 + 3 \cos 2 t$$
for \(0 < t < \pi\). The minimum point is \(M\) and the curve crosses the \(x\)-axis at points \(P\) and \(Q\).
- Show that \(\frac { \mathrm { d } y } { \mathrm {~d} x } = - 12 \cos t\).
- Find the coordinates of \(M\).
- Find the gradient of the curve at \(P\) and at \(Q\).