Practicing Success

Target Exam

CUET

Subject

-- Mathematics - Section B1

Chapter

Continuity and Differentiability

Question:

$\lim\limits_{x \rightarrow 0} \frac{\sqrt{1+\sin x}-\sqrt{1-\sin x}}{x}=$

Options:

1

2

0

none of these

Correct Answer:

1

Explanation:

$\lim\limits_{x \rightarrow 0} \frac{\sqrt{1+\sin x}-\sqrt{1-\sin x}}{x}$

$=\lim\limits_{x \rightarrow 0} \frac{\left(\cos \frac{x}{2}+\sin \frac{x}{2}\right)-\left(\sin \frac{x}{2}-\cos \frac{x}{2}\right)}{2}=\lim\limits_{x \rightarrow 0} \frac{2 \cos \frac{x}{2}}{2}=1$

Hence (1) is the correct answer.