Given f(x), write an equation for f -1(x) and then graph f(x) and f -1(x) on the same coordinate system. f(x) = x² - 9; x ≤ 0. Select one:
1) f -1(x) =
2) f -1(x) =
3) f -1(x) = -
4) f -1(x) = -