If f(x)=2x+2−xf(x) = 2^x + 2^{-x}f(x)=2x+2−x for x≥0x \geq 0x≥0, what is the inverse function f−1(x)f^{-1}(x)f−1(x)?
log2(x+x2−4)\log_2(x + \sqrt{x^2 - 4})log2(x+x2−4)
log2(x+x2−42)\log_2(\frac{x + \sqrt{x^2 - 4}}{2})log2(2x+x2−4)
log2(x−x2−4)\log_2(x - \sqrt{x^2 - 4})log2(x−x2−4)
log2(x+x2+42)\log_2(\frac{x + \sqrt{x^2 + 4}}{2})log2(2x+x2+4)