Answer
a) $f(x)= \begin{cases}x^2-4 & \text { for } x\leq -2\text{ or }x\geq 2
\\ -\left(x^2-4\right) & \text { for } -2
Work Step by Step
a) We have $f(x)= \begin{cases}x^2-4 & \text { for } \quad x^2-4 \geq 0 \\ -\left(x^2-4\right) & \text { for } \quad x^2-4<0\end{cases}$
or
$f(x)= \begin{cases}x^2-4 & \text { for } x\leq -2\text{ or }x\geq 2
\\ -\left(x^2-4\right) & \text { for } -2
