The graph of the function is:
From it we notice that the y-intercept is zero
From the graph we determine that the domaina and range are:
[tex]\begin{gathered} \text{domain}=(-\infty,\infty) \\ \text{range}=\lbrack-16,\infty) \end{gathered}[/tex]
The function is decreasing in the interval:
[tex](-\infty,4)[/tex]
And it is increasing in the interval:
[tex](4,\infty)[/tex]
