8.
\begin{figure}[h]
\includegraphics[alt={},max width=\textwidth]{7f5fc83d-ab7c-4edb-a2c6-7a58f1357d5a-24_579_642_251_715}
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\caption{Figure 3}
\end{figure}
Figure 3 shows a sketch of the curve \(C\) with parametric equations
$$x = 6 t - 3 \sin 2 t \quad y = 2 \cos t \quad 0 \leqslant t \leqslant \frac { \pi } { 2 }$$
The curve meets the \(y\)-axis at 2 and the \(x\)-axis at \(k\), where \(k\) is a constant.
- State the value of \(k\).
- Use parametric differentiation to show that
$$\frac { \mathrm { d } y } { \mathrm {~d} x } = \lambda \operatorname { cosec } t$$
where \(\lambda\) is a constant to be found.
The point \(P\) with parameter \(\mathrm { t } = \frac { \pi } { 4 }\) lies on \(C\).
The tangent to \(C\) at the point \(P\) cuts the \(y\)-axis at the point \(N\). - Find the exact \(y\) coordinate of \(N\), giving your answer in simplest form.
The region bounded by the curve, the \(x\)-axis and the \(y\)-axis is rotated through \(2 \pi\) radians about the \(x\)-axis to form a solid of revolution.
- Show that the volume of this solid is given by
$$\int _ { 0 } ^ { \alpha } \beta ( 1 - \cos 4 t ) d t$$
where \(\alpha\) and \(\beta\) are constants to be found.
- Hence, using algebraic integration, find the exact volume of this solid.