Find the Inverse of the Function $f ( x ) = - x ^ { 2 } + 12 , x \geq 0$

Multiple Choice

Find the inverse of the function.
- $f ( x ) = - x ^ { 2 } + 12 , x \geq 0$

A) $\mathrm { f } ^ { - 1 } ( \mathrm { x } ) = \sqrt { 12 - \mathrm { x } }$
B) $f ^ { - 1 } ( x ) = x ^ { 2 } + 12$
C) $f ^ { - 1 } ( x ) = \sqrt { x + 12 }$
D) $f ^ { - 1 } ( x ) = - \sqrt { x ^ { 2 } + 12 }$