Find the derivative of the function using the definition of derivative.
-$$f ( x ) = 5 x + 9$$
A) $f ^ { \prime } ( x ) = 9$
B) $f ^ { \prime } ( x ) = 0$
C) $f ^ { \prime } ( x ) = 5 x$
D) $f ^ { \prime } ( x ) = 5$

Question

Quizplus · Accepted Answer

The derivative of a linear function $f(x) = mx + b$ is the coefficient of $x$, which is $m$. For $f(x) = 5x + 9$, the derivative $f'(x)$ is $5$.

Find the Derivative of the Function Using the Definition of Derivative