Practicing Success

Target Exam

CUET

Subject

-- Mathematics - Section B1

Chapter

Application of Integrals

Question:

The area of the region bounded by the parabola $y^2 = 4ax$ and its latus rectum is:

Options:

$\frac{4a^2}{3}$ sq. unit

$\frac{8a^2}{3}$ sq. unit

$\frac{2a^2}{3}$ sq. unit

$\frac{9a^2}{5}$ sq. unit

Correct Answer:

$\frac{8a^2}{3}$ sq. unit

Explanation:

area of region I = area of region II by symmetry

area = 2 × area of region I

so,

area = $2 ×\int_0^a2\sqrt{ax}dx=4\sqrt{a}\left[\frac{2x^{3/2}}{3}\right]_0^a$

$=\frac{8a^2}{3}$ sq. unit