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WBJEE · Maths · Parabola

Let \(P\) and \(Q\) be the points on the parabola \(y^{2}=4 x\) so that the line segment \(P Q\) subtends right angle at the vertex. If \(P Q\) intersects the axis of the parabola at \(R,\) then the distance of the vertex from \(R\) is

  1. A 1
  2. B 2
  3. C 4
  4. D 6
Verified Solution

Answer & Solution

Correct Answer

(C) 4

Step-by-step Solution

Detailed explanation

According to question, it is given that slope of \(P X\) and \(Q X\) are perpendicular to each other, i.e., slope of \(P X \times\) slope of \(X Q=-1\) \(\Rightarrow \quad \frac{2 t}{t^{2}} \times \frac{2 m}{m^{2}}=-1\) \(\Rightarrow \quad t_{m}=-4\)…