AQA Paper 2 2020 June — Question 8

Exam BoardAQA
ModulePaper 2 (Paper 2)
Year2020
SessionJune
TopicParametric equations

8 The curve defined by the parametric equations $$x = t ^ { 2 } \text { and } y = 2 t \quad - \sqrt { 2 } \leq t \leq \sqrt { 2 }$$ is shown in Figure 1 below. \begin{figure}[h]
\captionsetup{labelformat=empty} \caption{Figure 1} \includegraphics[alt={},max width=\textwidth]{27339c29-c4a1-480c-b882-930f8dacc7af-13_1063_1022_607_507}
\end{figure} 8
  1. Find a Cartesian equation of the curve in the form \(y ^ { 2 } = \mathrm { f } ( x )\)
    8
  2. The point \(A\) lies on the curve where \(t = a\) The tangent to the curve at \(A\) is at an angle \(\theta\) to a line through \(A\) parallel to the \(x\)-axis. The point \(B\) has coordinates \(( 1,0 )\)
    The line \(A B\) is at an angle \(\phi\) to the \(x\)-axis.
    \includegraphics[max width=\textwidth, alt={}, center]{27339c29-c4a1-480c-b882-930f8dacc7af-14_846_936_678_552} 8
    1. By considering the gradient of the curve, show that $$\tan \theta = \frac { 1 } { a }$$ 8
  3. (ii) Find \(\tan \phi\) in terms of \(a\). 8
  4. (iii) Show that \(\tan 2 \theta = \tan \phi\)