Let f(x)=x2+1f(x) = x^2 + 1f(x)=x2+1 and g(x)=1xg(x) = \frac{1}{x}g(x)=x1. What is the domain of (g∘f)(x)(g \circ f)(x)(g∘f)(x)?
All real numbers
All real numbers except x=−1x = -1x=−1
All real numbers except x=1x = 1x=1
All real numbers except x=0x = 0x=0