Answer
(a) not a function. Domain $[0,4]$, Range $[-4,4]$
(b) function, domain $(-\infty,-1)\cup(-1,\infty)$, range $(-\infty,0)\cup(0,\infty)$, decreases over $(-\infty,-1)\cup(-1,\infty)$.
Work Step by Step
(a) The graph will not pass the vertical line test and it is not a function. Domain $[0,4]$, Range $[-4,4]$
(b) The graph is a function. We can identify its domain as $(-\infty,-1)\cup(-1,\infty)$, its range as $(-\infty,0)\cup(0,\infty)$. The function decreases over its entire domain $(-\infty,-1)\cup(-1,\infty)$.
