SOLUTION: what is the vertex of a parabola that is pointing downward and contains the points (-2,2), (0,1), and (1,2.5).

Question 336452: what is the vertex of a parabola that is pointing downward and contains the points (-2,2), (0,1), and (1,2.5).
Answer by Fombitz(32388) (Show Source): You can put this solution on YOUR website!
The general equation for a parabola is
Solve for ,, and using the points (,), (,), and (,).

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Simplify with

1.
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2.
Add eq. 1 and eq. 2 to eliminate ,

Then from eq. 3,

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Complete the square to put the equation into vertex form, where (,) is the vertex.

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Vertex:(,)
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The parabola opens upwards.
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