You can put this solution on YOUR website! Find the axis of symmetry.
y=x^2+3x-1
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Complete the square on the x terms and keep the equation balanced:
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x^2+3x+? = y+1+?
x^2+3x+(3/2)^2 = y+1+(3/2)^2
(x+(3/2))^2 = y+4/4 + 9/4
(x+(3/2))^2 = y+(13/4)
This tells you:
Vertex = (-3/2,-13/4)
Axis of symmetry is x=-3/2
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Cheers,
Stan H.