Functions Question 252

Question: If $ f(x)= \begin{cases} & x\sin \frac{1}{x},x\ne 0 \\ & k,x=0 \\ \end{cases} . $ is continuous at $ x=0 $ , then the value of k is

[MP PET 1999; AMU 1999; RPET 2003]

Options:

A) 1

B) ?1

C) 0

D) 2

Show Answer

Answer:

Correct Answer: C

Solution:

If function $ f(x) $ is continuous at $ x=0, $ then $ f(0)=\underset{x\to 0}{\mathop{\lim }}f(x) $ Given $ f(0)=k $ ; $ f(0)=k=\underset{x\to 0}{\mathop{\lim }}x,( \sin \frac{1}{x} ) $ $ f(0)=k=0,\text{ }( -1\le \sin \frac{1}{x}\le 1 ) $ ;
$ \therefore ,k=0 $ ..