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