Find range of f(x)=exf(x) = e^xf(x)=ex on R\mathbb{R}R.
[1,∞)[1, \infty)[1,∞)
[0,∞)[0, \infty)[0,∞)
(−∞,∞)(-\infty, \infty)(−∞,∞)
(0,∞)(0, \infty)(0,∞)