Find the range of f(x)=x2−1x2+1f(x) = \frac{x^2 - 1}{x^2 + 1}f(x)=x2+1x2−1.
(−1,1)(-1, 1)(−1,1)
[−1,1)[-1, 1)[−1,1)
[0,1)[0, 1)[0,1)
(−1,∞)(-1, \infty)(−1,∞)