Edexcel P4 2020 October — Question 4

Exam BoardEdexcel
ModuleP4 (Pure Mathematics 4)
Year2020
SessionOctober
TopicParametric equations

4. \begin{figure}[h]
\includegraphics[alt={},max width=\textwidth]{79ac81c3-cd05-4f28-8840-3c8a6960e7b7-10_833_822_127_561} \captionsetup{labelformat=empty} \caption{Figure 2}
\end{figure} Figure 2 shows a sketch of part of the curve with parametric equations $$x = 2 t ^ { 2 } - 6 t , \quad y = t ^ { 3 } - 4 t , \quad t \in \mathbb { R }$$ The curve cuts the \(x\)-axis at the origin and at the points \(A\) and \(B\), as shown in Figure 2.
  1. Find the coordinates of \(A\) and show that \(B\) has coordinates (20, 0).
  2. Show that the equation of the tangent to the curve at \(B\) is $$7 y + 4 x - 80 = 0$$ The tangent to the curve at \(B\) cuts the curve again at the point \(P\).
  3. Find, using algebra, the \(x\) coordinate of \(P\).