If f−1(x)=2x+1f^{-1}(x) = 2x + 1f−1(x)=2x+1, what is f(x)f(x)f(x)?
f(x)=x−12f(x) = \frac{x-1}{2}f(x)=2x−1
f(x)=x+12f(x) = \frac{x+1}{2}f(x)=2x+1
f(x)=2x−1f(x) = 2x - 1f(x)=2x−1
f(x)=x−1f(x) = x - 1f(x)=x−1