Question

The locus of a foot of perpendicular drawn to the tangent of parabola y² = 4ax from focus, is

(a) x = 0 

(b) y = 0 

(c) y² = 2a(x + a) 

(d) x² + y² (x + a) = 0

Answer 1

Correct option  (a) x = 0 

Explanation:

Tangent to parabola is, y = mx +a/m ....(i)

A line perpendicular to tangent and passing from focus (a, 0) is, y =-x/m +a/m ......(ii)

Solving both lines (i) and (ii) ⇒ x = 0 .