The length of the latus rectum of a parabola, whose vertex and focus are on the positive x-axis at a distance R and S ( R ) respectively from the origin, is:

Question

The length of the latus rectum of a parabola, whose vertex and focus are on the positive x-axis at a distance R and S (> R ) respectively from the origin, is: (A) 4( S + R ) (B) 2( S - R ) (C) 4( S - R ) (D) 2( S + R )

Tardigrade Admin · Accepted Answer

<img class="img-fluid question-image" alt="image" src="https://cdn.tardigrade.in/img/question/mathematics/4639d804bfed174a328bcbcaed97171d-.png" /> V arrow Vertex F arrow focus VF = S - R So latus rectum =4( S - R )

Q. The length of the latus rectum of a parabola, whose vertex and focus are on the positive $x$ -axis at a distance $R$ and $S (> R)$ respectively from the origin, is:

$4 (S + R)$

$2 (S - R)$

$4 (S - R)$

$2 (S + R)$

$V \to$ Vertex
$F \to$ focus
$V F = S - R$
So latus rectum $= 4 (S - R)$

Q. The length of the latus rectum of a parabola, whose vertex and focus are on the positive x-axis at a distance R and S(>R) respectively from the origin, is:

4(S+R)

2(S−R)

4(S−R)

2(S+R)