Q30Multiple correct4 Marks10 Jul 2022

The value of a quadratic function $f(x)$ increases over the interval $(-\infty,-5)$ and decreases over the interval $(-5,\infty)$. Also, $f(0)=f(-10)=20$. Which of the following statements about $f(x)$ can be true?

A

$f(x)$ is an injective function.

B

$D \geq 0$, where $D$ is the discriminant of $f(x)$.

C

$f(x)$ can be $-0.1(x+20)(x-10)$.

D

$f(x)$ can be $-0.1(x-20)(x+10)$.