8
5
- 2
\end{array} \right) + \mu \left( \begin{array} { r }
3
4
- 5
\end{array} \right)$$
where \(\lambda\) and \(\mu\) are scalar parameters and \(p\) is a constant.
The lines \(l _ { 1 }\) and \(l _ { 2 }\) intersect at the point \(A\).
- Find the coordinates of \(A\).
- Find the value of the constant \(p\).
- Find the acute angle between \(l _ { 1 }\) and \(l _ { 2 }\), giving your answer in degrees to 2 decimal places.
The point \(B\) lies on \(l _ { 2 }\) where \(\mu = 1\)
- Find the shortest distance from the point \(B\) to the line \(l _ { 1 }\), giving your answer to 3 significant figures.
- A curve \(C\) has parametric equations
$$x = 4 t + 3 , \quad y = 4 t + 8 + \frac { 5 } { 2 t } , \quad t \neq 0$$ - Find the value of \(\frac { \mathrm { d } y } { \mathrm {~d} x }\) at the point on \(C\) where \(t = 2\), giving your answer as a fraction in its simplest form.
- Show that the cartesian equation of the curve \(C\) can be written in the form
$$y = \frac { x ^ { 2 } + a x + b } { x - 3 } , \quad x \neq 3$$
where \(a\) and \(b\) are integers to be determined.
6.
\begin{figure}[h]
\includegraphics[alt={},max width=\textwidth]{89d4a7a5-3f4f-4d16-b14e-a27243cedd78-11_666_993_244_392}
\captionsetup{labelformat=empty}
\caption{Diagram not to scale}
\end{figure}
Figure 2
Figure 2 shows a sketch of the curve with equation \(y = \sqrt { ( 3 - x ) ( x + 1 ) } , 0 \leqslant x \leqslant 3\)
The finite region \(R\), shown shaded in Figure 2, is bounded by the curve, the \(x\)-axis, and the \(y\)-axis. - Use the substitution \(x = 1 + 2 \sin \theta\) to show that
$$\int _ { 0 } ^ { 3 } \sqrt { ( 3 - x ) ( x + 1 ) } d x = k \int _ { - \frac { \pi } { 6 } } ^ { \frac { \pi } { 2 } } \cos ^ { 2 } \theta d \theta$$
where \(k\) is a constant to be determined.
- Hence find, by integration, the exact area of \(R\).
7. (a) Express \(\frac { 2 } { P ( P - 2 ) }\) in partial fractions.
A team of biologists is studying a population of a particular species of animal.
The population is modelled by the differential equation
$$\frac { \mathrm { d } P } { \mathrm {~d} t } = \frac { 1 } { 2 } P ( P - 2 ) \cos 2 t , t \geqslant 0$$
where \(P\) is the population in thousands, and \(t\) is the time measured in years since the start of the study.
Given that \(P = 3\) when \(t = 0\),
- solve this differential equation to show that
$$P = \frac { 6 } { 3 - \mathrm { e } ^ { \frac { 1 } { 2 } \sin 2 t } }$$
- find the time taken for the population to reach 4000 for the first time.
Give your answer in years to 3 significant figures.
8.
\begin{figure}[h]
\includegraphics[alt={},max width=\textwidth]{89d4a7a5-3f4f-4d16-b14e-a27243cedd78-15_696_1418_287_262}
\captionsetup{labelformat=empty}
\caption{Figure 3}
\end{figure}
Figure 3 shows a sketch of part of the curve \(C\) with equation
$$y = 3 ^ { x }$$
The point \(P\) lies on \(C\) and has coordinates \(( 2,9 )\).
The line \(l\) is a tangent to \(C\) at \(P\). The line \(l\) cuts the \(x\)-axis at the point \(Q\). - Find the exact value of the \(x\) coordinate of \(Q\).
The finite region \(R\), shown shaded in Figure 3, is bounded by the curve \(C\), the \(x\)-axis, the \(y\)-axis and the line \(l\). This region \(R\) is rotated through \(360 ^ { \circ }\) about the \(x\)-axis.
- Use integration to find the exact value of the volume of the solid generated.
Give your answer in the form \(\frac { p } { q }\) where \(p\) and \(q\) are exact constants.
[0pt]
[You may assume the formula \(V = \frac { 1 } { 3 } \pi r ^ { 2 } h\) for the volume of a cone.]