Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
99 Percentile Qs Bank for JEE MainMathematicsParabola

Through the vertex O of a parabola y 2 = 4 ax , chords O P   &   O Q are drawn at right angles to one another. Then The locus of midpoints of the chord P Q is :

Options

  1. Ay 2 = 2 a x - 8 a 2
  2. By 2 = 2 a x + 8 a 2
  3. Cy 2 = 2 a x + 4 a 2
  4. Dy 2 = 2 a x - 4 a 2

Correct answer

A. y 2 = 2 a x - 8 a 2

Step-by-step solution

If x , y be the mid point of P Q , then 2 x = a t 1 2 + t 2 2 & 2 y = 2 a t 1 + t 2 or 2 x = a [ t 1 + t 2 2 - 2 t 1 t 2 ] or 2 x = a y 2 a 2 - 2 t 1 t 2     . . .(1)   &   y a = t 1 + t 2     . . . (2) As we know that condition for the chord P Q to subtend a right angle at the vertex of the parabola is t 1 t 2 = - 4 [Since P Q subtends a right angle at vertex O ( 0 , 0 ) , O P   &   O Q   are perpendicular i.e., m 1 m 2 = - 1 or 2 a t 1 a t 1 2 · 2 a t 2 a

Practice Parabola on Quantrex Academy →

More from Parabola

Let T be the tangent to the parabola y^2 = 16x at the point (64, 32) . Let L be the tangent to the same parabola at another point (x₁, y₁) on the parabola. If L and T are perpendic 2026Let O be the vertex of the parabola y^2=4x and its chords OP and OQ are perpendicular to each other. If the locus of the mid-point of the line segment PQ is a conic C, then the len 2026Let chord PQ of length 3 13 of the parabola y^2 = 12x be such that the ordinates of points P and Q are in the ratio 1:2 . If the chord PQ subtends an angle at the focus of the para 2026Let the point P be the vertex of the parabola y = x^2 - 6x + 12 . If a line passing through the point P intersects the circle x^2 + y^2 - 2x - 4y + 3 = 0 at the points R and S , th 2026Let the directrix of the parabola P: y^2 = 8x , cut x -axis at the point A . Let B( , ) , > 1 , be a point on P such that the slope of AB is 3/5 . If BC is a focal chord of P , the 2026Let A,B and C be the vertices of a variable right angled triangle inscribed in the parabola y^2=16x . Let the vertex B containing the right angle be (4,8) and the locus of the cent 2026Consider the parabola P : y^2 = 4kx and the ellipse E : x^2 a^2 + y^2 b^2 = 1 . Let the line segment joining the points of intersection of P and E , be their latus rectums. If the 2026Let the parabola y = x^2 + px + q passing through the point (1, -1) be such that the distance between its vertex and the x -axis is minimum. Then the value of p^2 + q^2 is: 2026 Full Parabola list All 99 Percentile Qs Bank for JEE Main PYQs