Question 64772
y=x^2+2x-9 - how would one find the vertex
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The minimum or maximum occurs when x=-b/2a
In your case x=-2/2=-1
The corresponding y value is:
f(-1)=(-1)^2+2(-1)-9
f(-1)=1-2-9=-10
The vertex is at (-1,-10)
{{{graph(600,400,-10,10,-10,10,x^2+2x-9)}}}
Cheers,
Stan H.