The derivative of $f ( x ) = \sqrt { x } - 4$ at x = 4 is

A)-4
B) $- \frac { 1 } { 4 }$
C) $- \frac { 1 } { 2 }$
D) $\frac { 1 } { 4 }$
E) $\frac { 1 } { 2 }$

Name: The derivative of $f ( x ) = \sqrt { x } - 4$ at x = 4 is A)-4 B) $- \frac { 1 } { 4 }$ C) $- \frac { 1 } { 2 }$ D) $\frac { 1 } { 4 }$ E) $\frac { 1 } { 2 }$
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Question

The derivative of $f ( x ) = \sqrt { x } - 4$ at x = 4 is

A)-4
B) $- \frac { 1 } { 4 }$
C) $- \frac { 1 } { 2 }$
D) $\frac { 1 } { 4 }$
E) $\frac { 1 } { 2 }$

Quizplus · Accepted Answer

The derivative of $f(x) = \sqrt{x} - 4$ is $f'(x) = \frac{1}{2\sqrt{x}}$. Substituting $x = 4$ gives $f'(4) = \frac{1}{2\sqrt{4}} = \frac{1}{4}$.

The Derivative Of f(x)=x−4f ( x ) = \sqrt { x } - 4f(x)=x​−4

The Derivative Of $f ( x ) = \sqrt { x } - 4$