Question

Let $f\left(x\right)=4-x^2$ then $f\left(x\right)$ has greatest value at $x=?$

• A. 1
• B. -1
• C. 0
• D. 2

Answer 1

The correct option is C 0

$f\left(x\right)=4-x^2$

The max value of $f\left(x\right)$ is given as $f^{\prime }\left(x\right)=0$

$f^{\prime }\left(x\right)=-2x=0x=0$

So it has greatest value at $x=0$