Which of the following describes the behavior of f(x)=(12)xf(x) = (\frac{1}{2})^xf(x)=(21)x as x→∞x \to \inftyx→∞?
f(x)→∞f(x) \to \inftyf(x)→∞
f(x)→1f(x) \to 1f(x)→1
f(x)→0f(x) \to 0f(x)→0
f(x)→−∞f(x) \to -\inftyf(x)→−∞