SOLUTION: Find the vertex of quadratic equation f(x) = 2x^2 + 4x-9 (2x squared plus 4x minus 9) This is what I have so far until I get lost: step one: y= 2x^ + 4x - 9 step two: y+9=2

Algebra ->  Quadratic Equations and Parabolas  -> Quadratic Equation Customizable Word Problems -> SOLUTION: Find the vertex of quadratic equation f(x) = 2x^2 + 4x-9 (2x squared plus 4x minus 9) This is what I have so far until I get lost: step one: y= 2x^ + 4x - 9 step two: y+9=2      Log On


   

Question 148667: Find the vertex of quadratic equation f(x) = 2x^2 + 4x-9
(2x squared plus 4x minus 9)
This is what I have so far until I get lost:
step one: y= 2x^ + 4x - 9
step two: y+9=2x^2 +4x
step three:y+9=2(x^2 +2x)
(half of 2=1 ; (1)^2 =1
Not sure where to go after this. thanks!

Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
Find the vertex of quadratic equation f(x) = 2x^2 + 4x-9
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It looks like you are trying to complete the square:
2x^2+4x = y+9
2(x^2+2x+1) = y+9+2
2(x+1)^2 = y+11
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Vertex is at (-1,-11)
graph%28400%2C300%2C-10%2C10%2C-15%2C50%2C2x%5E2%2B4x-9%29
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Cheers,
Stan H.