Most Important Selected Qs for JEE AdvancedMathematicsParabola
P Q is a double ordinate of the parabola y^2=4 a x . If the normal at P intersect the line passing through Q and parallel to x -axis at G then locus of G is a parabola with
Options
- Alength of latus rectum equal to 4a
- Bvertex at (4a, 0)
- Cdirectrix as the line x – 3a = 0
- Dfocus at (5a, 0)
Correct answer
D. focus at (5a, 0)
Step-by-step solution
N: y+t x=2 a t+a t^3L: y=-2 a t On solving together -2 a t+t x=2 a t+a t^3x=a t^2+4 a Hence h=a t^2+4 a....(i)k=-2 a t....(ii) So y^2=4 a(x-4 a) (eliminating .t ) Now verify alternatives