Find the Instantaneous Rate of Change of the Function $f ( x ) = \sqrt { 3 x }$

Multiple Choice

Find the instantaneous rate of change of the function $f ( x ) = \sqrt { 3 x }$ when $x = 3$ .

A) $\frac { 1 } { 3 }$
B) 3
C) 9
D) $\frac { 1 } { 2 }$