Find the Inverse of the Function $$f ( x ) = \sqrt { 2 x + 1 }$$

Multiple Choice

Find the inverse of the function.
- $$f ( x ) = \sqrt { 2 x + 1 }$$

A) $f ^ { - 1 } ( x ) = \frac { ( x - 1 ) ^ { 2 } } { 2 }$ for $x \geq 0$
B) $f ^ { - 1 } ( x ) = \frac { x ^ { 2 } } { 2 } - 1$ for $x \geq 0$
C) $\mathrm { f } ^ { - 1 } ( \mathrm { x } ) = \frac { 2 \mathrm { x } - 1 } { 2 }$
D) $\mathrm { f } ^ { - 1 } ( \mathrm { x } ) = \frac { \mathrm { x } ^ { 2 } - 1 } { 2 }$ for $x \geq 0$