Practicing Success

Target Exam

CUET

Subject

-- Mathematics - Section A

Chapter

Definite Integration

Question:

$\int\limits_0^{\pi / 2} \frac{d x}{1+\tan ^3 x}$ is :

Options:

0

1

$\frac{\pi}{2}$

$\frac{\pi}{4}$

Correct Answer:

$\frac{\pi}{4}$

Explanation:

$I=\int\limits_0^{\pi / 2} \frac{\cos ^3 x}{\sin ^3 x+\cos ^3 x} d x$

$I=\int\limits_0^{\pi / 2} \frac{\sin ^3 x}{\sin ^3 x+\cos ^3 x} d x \Rightarrow 2 I=\int\limits_0^{\pi / 2} dx \Rightarrow I=\frac{\pi}{4}$

Hence (4) is the correct answer.