Question 328402
DUPLICATE 
Previously answered See Answer 235190.


It opens downward because the {{{x^2}}} coefficient is negative (-4).
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It's in vertex form {{{y=a(x-h)^2+k}}} where (h,k) is the vertex.
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,-6,6,-2,10,grid(1),circle(-1,8,.25),graph(300,300,-6,6,-2,10,-4(x+1)^2+8))}}}