Mathematics

Problem

Which of the following function(s) defined at

x = 0

has/have removable discontinuity at the origin? a.

f(x) = \frac{1}{1 + 2 \cot x}

f(x) = \cos \left( \frac{|\sin x|}{x} \right)

f(x) = x \sin \frac{\pi}{x}

f(x) = \frac{1}{\ln |x|}