Q8 Q9 Q12


Q8. The triangle PQR of area 'A' is inscribed in the parabola y² = 4 ax such that the vertex P lies at the vertex of the parabola and base QR is a focal chord. The modulus of the difference of the ordinates of the points Q and R is-

  (A) $\frac{\mathrm{A}}{2\mathrm{a}}$                 (B) $\frac{\mathrm{A}}{\mathrm{a}}$                       (C) ​$\frac{2\mathrm{A}}{\mathrm{a}}$                     (D) ​$\frac{4\mathrm{A}}{\mathrm{a}}$

Q9. Point P lies on y² = 4ax & N is foot of perpendicular from P on its axis. A straight line is drawn parallel to the axis to bisect NP and meets the curve in Q. NQ meets the tangent at the vertex in a point T such that AT = k NP, then the value of k is : (where A is the vertex)

   (A) 3/2                             (B) 2/3                         (C) 1                           (D) none


Q12. T is a point on the tangent to a parabola y² = 4ax at its point P. TL and TN are the perpendiculars on the focal radius SP and the directrix of the parabola respectively. Then-


     (A) SL = 2 (TN)            (B) 3 (SL) = 2 (TN)      (C) SL = TN              (D) 2 (SL) =3 (TN)