Edexcel FP1 2015 June — Question 8

Exam BoardEdexcel
ModuleFP1 (Further Pure Mathematics 1)
Year2015
SessionJune
TopicConic sections

  1. The point \(P \left( 3 p ^ { 2 } , 6 p \right)\) lies on the parabola with equation \(y ^ { 2 } = 12 x\) and the point \(S\) is the focus of this parabola.
    1. Prove that \(S P = 3 \left( 1 + p ^ { 2 } \right)\)
    The point \(Q \left( 3 q ^ { 2 } , 6 q \right) , p \neq q\), also lies on this parabola.
    The tangent to the parabola at the point \(P\) and the tangent to the parabola at the point \(Q\) meet at the point \(R\).
  2. Find the equations of these two tangents and hence find the coordinates of the point \(R\), giving the coordinates in their simplest form.
  3. Prove that \(S R ^ { 2 } = S P \cdot S Q\)