For the function defined by f(x)=2-x^2, 0<=x, use a sketch to find formula for f^-1(x)…?

Answer 1

If y = 2 - x^2 and x >= 0, f^-1 is: x = sqrt(2 - y) or for
f(x) = 2 - x^2,
f^-1(x) = sqrt(2 - x).
Using a sketch the inverse function is horizontal parabola opening toward negative x (only the upper part) with value = 0 at x = 2. It doesn't exist for x <= 2.