JEE Main 2022 · 27 Jul · Shift 2 · Mathematics Q13

MathematicsSingle correct+4 / -1Question 13 of 90

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

2\sqrt2

2\sqrt3

4\sqrt2

Answer and worked solution

Official answer: C

Focal length is the distance from the focus to the tangent at the vertex: $\frac{|a|}{\sqrt2}=\frac{16}4$ , so $|a|=4\sqrt2$ .

(C)

Topics:Parabola Distance of a point from a line

JEE Main 2022 · 27 Jul · Shift 2, Mathematics question 13