Calculate the derivative of the function. Then find the value of the derivative as specified.
-$$f ( x ) = 5 x + 9 ; f ^ { \prime } ( 2 )$$
A) $f ^ { \prime } ( x ) = 9 ; f ^ { \prime } ( 2 ) = 9$
B) $f ^ { \prime } ( x ) = 5 ; f ^ { \prime } ( 2 ) = 5$
C) $f ^ { \prime } ( x ) = 5 x ; f ^ { \prime } ( 2 ) = 10$
D) $\mathrm { f } ^ { \prime } ( \mathrm { x } ) = 0 ; \mathrm { f } ^ { \prime } ( 2 ) = 0$

Question

Quizplus · Accepted Answer

The derivative of a linear function like $f(x)=mx+b$ is simply the slope $m$. Therefore, $f'(x)=5$. 
To find $f'(2)$, we substitute $x=2$ into the derivative: $f'(2)=5$.

Calculate the Derivative of the Function f(x)=5x+9;f′(2)f ( x ) = 5 x + 9 ; f ^ { \prime } ( 2 )f(x)=5x+9;f′(2)

Calculate the Derivative of the Function $f ( x ) = 5 x + 9 ; f ^ { \prime } ( 2 )$