Practicing Success

Target Exam

CUET

Subject

-- Mathematics - Section B1

Chapter

Determinants

Question:

The area lying between the curves y2 = 4x and y = 2x is :

Options:

$\frac{2}{3}$

1

$\frac{1}{3}$

$\frac{1}{4}$

Correct Answer:

$\frac{1}{3}$

Explanation:

y2 = 4x  ,    y = 2x

point of intersection

y = 2x        y2 = 4x

⇒ (2x)2 = 4x

⇒ x2 = x

⇒ x = 1, 0

area = area under y2 = 4x - area under y = 2x

so area = $\int\limits_0^1-2 x+2 \sqrt{x} d x$

$=\left[-x^2+\frac{4}{3} x^{3 / 2}\right]_0^1=\frac{4}{3}-1$

$= \frac{1}{3}$ sq. units