Which of the following functions have an infinite discontinuity at x=1x=1x=1?
f(x)=1x−1f(x) = \frac{1}{x-1}f(x)=x−11
f(x)=1(x−1)2f(x) = \frac{1}{(x-1)^2}f(x)=(x−1)21
f(x)=ln(x−1)f(x) = \ln(x-1)f(x)=ln(x−1) for x>1x>1x>1
f(x)=sin(x−1)f(x) = \sin(x-1)f(x)=sin(x−1)