Compute $f ^ { \prime } ( 3 )$ .
$f ( x ) = 2.9 x ^ { 2 } - 5.7 x$
A) $f ^ { \prime } ( 3 ) = 17.4$
B) $f ^ { \prime } ( 3 ) = 0.1$
C) $f ^ { \prime } ( 3 ) = 11.7$
D) $f ^ { \prime } ( 3 ) = 3$
E) $f ^ { \prime } ( 3 ) = 11.5$

Question

Compute $f ^ { \prime } ( 3 )$ .  
  $f ( x ) = 2.9 x ^ { 2 } - 5.7 x$  
A)  $f ^ { \prime } ( 3 ) = 17.4$
B)   $f ^ { \prime } ( 3 ) = 0.1$
C)   $f ^ { \prime } ( 3 ) = 11.7$
D)   $f ^ { \prime } ( 3 ) = 3$
E)   $f ^ { \prime } ( 3 ) = 11.5$

Quizplus · Accepted Answer

The derivative of $f(x) = 2.9x^2 - 5.7x$ is $f'(x) = 5.8x - 5.7$. Evaluating at $x = 3$, $f'(3) = 5.8(3) - 5.7 = 17.4 - 5.7 = 11.7$.

Compute f′(3)f ^ { \prime } ( 3 )f′(3) f(x)=2.9x2−5.7xf ( x ) = 2.9 x ^ { 2 } - 5.7 xf(x)=2.9x2−5.7x

Compute $f ^ { \prime } ( 3 )$ $f ( x ) = 2.9 x ^ { 2 } - 5.7 x$