AQA FP1 2016 June — Question 7 11 marks

Exam BoardAQA
ModuleFP1 (Further Pure Mathematics 1)
Year2016
SessionJune
Marks11
TopicComplex Numbers Arithmetic
TypeParametric polynomials with root conditions

7
  1. Solve the equation \(x ^ { 2 } + 4 x + 20 = 0\), giving your answers in the form \(c + d \mathrm { i }\), where \(c\) and \(d\) are integers.
  2. The roots of the quadratic equation $$z ^ { 2 } + ( 4 + i + q i ) z + 20 = 0$$ are \(w\) and \(w ^ { * }\).
    1. In the case where \(q\) is real, explain why \(q\) must be - 1 .
    2. In the case where \(w = p + 2 \mathrm { i }\), where \(p\) is real, find the possible values of \(q\).
      [0pt] [5 marks] \(8 \quad\) The matrix \(\mathbf { A }\) is defined by \(\mathbf { A } = \left[ \begin{array} { l l } 2 & 0
      0 & 1 \end{array} \right]\).
    1. Find the matrix \(\mathbf { A } ^ { 2 }\).
    2. Describe fully the single geometrical transformation represented by the matrix \(\mathbf { A } ^ { 2 }\).
  3. Given that the matrix \(\mathbf { B }\) represents a reflection in the line \(x + \sqrt { 3 } y = 0\), find the matrix \(\mathbf { B }\), giving the exact values of any trigonometric expressions.
  4. Hence find the coordinates of the point \(P\) which is mapped onto \(( 0 , - 4 )\) under the transformation represented by \(\mathbf { A } ^ { 2 }\) followed by a reflection in the line \(x + \sqrt { 3 } y = 0\).
    [0pt] [6 marks] \(9 \quad\) A curve \(C\) has equation \(y = \frac { x - 1 } { ( x - 2 ) ( 2 x - 1 ) }\).
    The line \(L\) has equation \(y = \frac { 1 } { 2 } ( x - 1 )\).
  5. Write down the equations of the asymptotes of \(C\).
  6. By forming and solving a suitable cubic equation, find the \(x\)-coordinates of the points of intersection of \(L\) and \(C\).
  7. Given that \(C\) has no stationary points, sketch \(C\) and \(L\) on the same axes.
  8. Hence solve the inequality \(\frac { x - 1 } { ( x - 2 ) ( 2 x - 1 ) } \geqslant \frac { 1 } { 2 } ( x - 1 )\).