Question

The maximum value of $f\left(x\right)=x^2+7x+9$ is

• A. $9$
• B. $\frac{13}{4}$
• C. $-\frac{13}{4}$
• D. not defined

Answer 1

The correct option is D not defined

$f\left(x\right)=x^2+7x+9,a=1>0$
$\Rightarrow$ Minimum value is $\frac{4ac-b^2}{4a}$ and maximum value is not defined.