Determine All Critical Points for the Function $$f ( x ) = \frac { 3 x } { x + 2 }$$

Multiple Choice

Determine all critical points for the function.
- $$f ( x ) = \frac { 3 x } { x + 2 }$$

A) $x = 6$ and $x = 0$
B) $x = - 2$
C) $x = 2$
D) $x = 0$ and $x = - 2$