Find the range of the function f(x)=ex−e−xex+e−xf(x) = \frac{e^x - e^{-x}}{e^x + e^{-x}}f(x)=ex+e−xex−e−x for x∈Rx \in \mathbb{R}x∈R.
(−1,1)(-1, 1)(−1,1)
[0,1)[0, 1)[0,1)
(−∞,∞)(-\infty, \infty)(−∞,∞)
(−1,0)(-1, 0)(−1,0)