Functions Question 163

Question: $ \underset{x\to \infty }{\mathop{\lim }},\sqrt{\frac{x+\sin x}{x-\cos x}}= $

[Roorkee 1994]

Options:

A) 0

B) 1

C) ?1

D) None of these

Show Answer

Answer:

Correct Answer: B

Solution:

$ \underset{x\to \infty }{\mathop{\lim }},\sqrt{( \frac{x+\sin x}{x-\cos x} )}=\underset{x\to \infty }{\mathop{\lim }}\sqrt{( \frac{1+\frac{\sin x}{x}}{1-\frac{\cos x}{x}} )}=\underset{x\to \infty }{\mathop{\lim }},\sqrt{1}=1 $ $ [,\because \underset{x\to \infty }{\mathop{\lim }}\frac{\sin x}{x} $ and $ \underset{x\to \infty }{\mathop{\lim }}\frac{\cos x}{x} $ both are equal to 0]