Find the Derivative of the Function Using the Definition of Derivative

Multiple Choice

Find the derivative of the function using the definition of derivative.
- $$f ( x ) = x ^ { 3 } + 5 x$$

A) $f ^ { \prime } ( x ) = x ^ { 2 } + 5$
B) $f ^ { \prime } ( x ) = 3 x ^ { 2 } + 5 x$
C) $f ^ { \prime } ( x ) = 3 x ^ { 2 }$
D) $f ^ { \prime } ( x ) = 3 x ^ { 2 } + 5$