Question

If the length of the latus rectum of a parabola whose focus is (a,a) and tangent at its vertex is x + y = a, is 16. Then |a| is equal to:

(a) 2√3

(b) 2√2

(c) 4√2

(d) 4

Answer 1

Correct option is (c) 4√2

Length of perpendicular from focus to tangent at vertex:

So length of latus rectum will be, 4l = 16