Practicing Success

Target Exam

CUET

Subject

-- Mathematics - Section B1

Chapter

Continuity and Differentiability

Question:

$\lim\limits_{x \rightarrow 5 \pi / 4}[\sin x+\cos x]$, where [.] denotes the integral part of x

Options:

Is equal to –1

Is equal to –2

Is equal to –3

Does not exist

Correct Answer:

Is equal to –2

Explanation:

Given limit is

$\lim\limits_{x \rightarrow \frac{5-\pi}{4}}\left[\sqrt{2} \sin \left(x+\frac{\pi}{4}\right)\right]$

$\lim\limits_{x \rightarrow \frac{5-\pi}{4}+}\left[\sqrt{2} \sin \left(x+\frac{\pi}{4}\right)\right]=-2, \lim\limits_{x \rightarrow \frac{5-\pi}{4}-}\left[\sqrt{2} \sin \left(x+\frac{\pi}{4}\right)\right]=-2$

Hence (2) is the correct answer.