<PRE><B>Question 137048</B>
i need the vertex of equation y equals -x^2+2x+3
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You have a quadratic with a=-1, b=2, and c = 3
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The vertex occurs when x = -b/2a = -2/-2 = 1
The corresponding y value is -(1^2)+2*1+3 = 4
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Vertex: (1,4)
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See it:
{{{graph(400,300,-10,10,-10,10,-x^2+2x+3)}}}
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Cheers,
Stan H.</PRE>