Answer
(a) See graph, opens up, vertex $(-3,0)$, axis of symmetry $x=-3$, y-intercept $(0,9)$, x-intercept(s) $(-3,0)$.
(b) domain $(-\infty,\infty)$, range $[0,\infty)$.
(c) increasing on $(-3,\infty)$, decreasing on $(-\infty,-3)$.
Work Step by Step
(a) See graph for $y=x^2+6x+9=(x+3)^2+0$, we can find that the graph opens up, vertex $(-3,0)$, axis of symmetry $x=-3$, y-intercept $(0,9)$, x-intercept(s) $(-3,0)$.
(b) We can determine the domain $(-\infty,\infty)$, range $[0,\infty)$.
(c) The function is increasing on $(-3,\infty)$, decreasing on $(-\infty,-3)$.
