Answer
(a) See graph, opens up, vertex $(1,-4)$, axis of symmetry $x=1$, y-intercept $(0,-3)$, x-intercept(s) $(3,0),(-1,0)$.
(b) domain $(-\infty,\infty)$, range $[-4,\infty)$.
(c) increasing on $(1,\infty)$, decreasing on $(-\infty,1)$.
Work Step by Step
(a) See graph for $y=x^2-2x-3=(x-1)^2-4$, we can find that the graph opens up, vertex $(1,-4)$, axis of symmetry $x=1$, y-intercept $(0,-3)$, x-intercept(s) $(3,0),(-1,0)$.
(b) We can determine the domain $(-\infty,\infty)$, range $[-4,\infty)$.
(c) The function is increasing on $(1,\infty)$, decreasing on $(-\infty,1)$.
