Question 328374
The equation is in vertex form {{{y=a(x-h)^2+k}}} where (h,k) is the vertex.
(h,k)=(-2,-8)
The vertex lies on the line of symmetry, {{{x=-2}}} 
If the parabola opens upwards, the vertex y coordinate is the minimum y value.
If the parabola opens downwards, the vertex y coordinate is the maximum y value.
In this case, {{{ymax=-8}}}
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{{{drawing(300,300,-8,8,-14,2,blue(line(-2,-20,-2,20)),grid(1),circle(-2,-8,.2),graph(300,300,-8,8,-14,2,-(x+2)^2-8))}}}