Let f be defined by
\(f(x) = \left\{ \begin{array}{cl} 2-x & \text{ if } x \leq 1, \\ 2x-x^2 & \text{ if } x>1. \end{array} \right.\)
Calculate \(f^{-1}(-3)+f^{-1}(0)+f^{-1}(3)\).
The answer is 2 + 6 + (-1) = 7.