What is the range of f(x)=1x2+1f(x) = \frac{1}{x^2+1}f(x)=x2+11?
(0,∞)(0, \infty)(0,∞)
(0,1](0, 1](0,1]
[0,1)[0, 1)[0,1)
(1,∞)(1, \infty)(1,∞)