$$\begin{aligned}
& l _ { 1 } : \mathbf { r } = \left( \begin{array} { c }
10 \\
3
\end{array} \right) + \lambda \left( \begin{array} { c }
2 \\
- 2 \\
1
\end{array} \right) \\
& l _ { 2 } : \mathbf { r } = \left( \begin{array} { l }
5 \\
2 \\
4
\end{array} \right) + \mu \left( \begin{array} { c }
3 \\
1 \\
- 2
\end{array} \right)
\end{aligned}$$
\(P\) is the point of intersection of \(l _ { 1 }\) and \(l _ { 2 }\).
- Find the position vector of \(P\).
- Find, correct to 1 decimal place, the acute angle between \(l _ { 1 }\) and \(l _ { 2 }\).
\(Q\) is a point on \(l1\) which is 12 metres away from \(P \cdot R\) is the point on \(l2\) such that \(QR\) is perpendicular to \(l1\).
- Determine the length \(QR\).
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5. (a) Express \(\frac { 5 + 4 x - 3 x ^ { 2 } } { ( 1 - 2 x ) ( 2 + x ) ^ { 2 } }\) in three partial fractions.
(b)
Hence find the first three terms in the expansion of \(\frac { 5 + 4 x - 3 x ^ { 2 } } { ( 1 - 2 x ) ( 2 + x ) ^ { 2 } }\) in ascending powers of \(x\).
(c) State the set of values for which the expansion in part (b) is valid.
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6.
The matrices \(\mathbf { A }\) and \(\mathbf { B }\) are given by \(\mathbf { A } = \left( \begin{array} { l l } 1 & a \\ 3 & 0 \end{array} \right)\) and \(\mathbf { B } = \left( \begin{array} { l l } 4 & 2 \\ 3 & 3 \end{array} \right)\).
(a) Find the value of a such that \(\mathbf { A B } = \mathbf { B A }\).
(b) Prove by counter example that matrix multiplication for \(2 \times 2\) matrices is not commutative.
(c) A triangle of area 4 square units is transformed by the matrix \(\mathbf { B }\). Find the area of the image of the triangle following this transformation. - Find the equations of the invariant lines of the form \(y = m x\) for the transformation represented by matrix \(\mathbf { B }\).
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7. (a) In this question you must show detailed reasoning.
Find the roots of the equation \(2 z ^ { 2 } - 2 z + 5 = 0\).
(b) The loci \(C _ { 1 }\) and \(C _ { 2 }\) are given by \(| z | = | z - 2 i |\) and \(| z - 2 | = \sqrt { 5 }\) respectively.
i. Sketch on a single Argand diagram the loci \(C _ { 1 }\) and \(C _ { 2 }\), showing any intercepts with the imaginary axis.
ii. Indicate, by shading on your Argand diagram, the region \(\{ z : | z | \leqslant | z - 2 \mathrm { i } | \} \cap \{ z : | z - 2 | \leqslant \sqrt { 5 } \}\).
(c) i. Show that both of the roots of the equation \(2 z ^ { 2 } - 2 z + 5 = 0\) satisfy \(| z - 2 | < \sqrt { 5 }\).
ii. State, with a reason, which root of the equation \(2 z ^ { 2 } - 2 z + 5 = 0\) satisfies \(| z | < | z - 2 i |\).
(d) On the same Argand diagram as part (b), indicate the positions of the roots of the equation \(2 z ^ { 2 } - 2 z + 5 = 0\).
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