Find the Inverse of the Function $$f ( x ) = \sqrt { x + 9 }$$

Multiple Choice

Find the inverse of the function.
- $$f ( x ) = \sqrt { x + 9 }$$

A) $f ^ { - 1 } ( x ) = \sqrt { x - 9 }$
B) $\mathrm { f } ^ { - 1 } ( \mathrm { x } ) = \mathrm { x } ^ { 2 } - 9 , x \geq 0$
C) Not a one-to-one function
D) $f ^ { - 1 } ( x ) = ( x + 9 ) ^ { 2 }$