Which of these functions is odd?
f(x)=x2+1f(x) = x^2 + 1f(x)=x2+1
f(x)=x3−xf(x) = x^3 - xf(x)=x3−x
f(x)=sin(x)+1f(x) = \sin(x) + 1f(x)=sin(x)+1
f(x)=∣x∣f(x) = |x|f(x)=∣x∣