SOLUTION: Without graphing, determine whether the following paraholas opens upward or downward and find the vertex. g(x)=-4(x+1)^2+8 I know it opens downward and the vertex

Algebra ->  Linear-equations -> SOLUTION: Without graphing, determine whether the following paraholas opens upward or downward and find the vertex. g(x)=-4(x+1)^2+8 I know it opens downward and the vertex       Log On


   

Question 328372: Without graphing, determine whether the following paraholas opens upward or
downward and find the vertex.
g(x)=-4(x+1)^2+8

I know it opens downward and the vertex is (-1,8) I just don't know how it was
found. Can you please help.

Thanks

Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
It opens downward because the x%5E2 coefficient is negative (-4).
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It's in vertex form y=a%28x-h%29%5E2%2Bk 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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