SOLUTION: give the coordinates of the focus and the equation of the directrix for the parabola with equation y=-(1/2)x2

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: give the coordinates of the focus and the equation of the directrix for the parabola with equation y=-(1/2)x2      Log On


   

Question 200171: give the coordinates of the focus and the equation of the directrix for the parabola with equation y=-(1/2)x2
Answer by RAY100(1637) About Me  (Show Source):
You can put this solution on YOUR website!
y = (-1/2) x^2
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-2y = x^2,,,,,but x^2 = 4py ( standard form)
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4py = -2y
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p = -1/2 ,,,,,,focus (0,p),,,, or focus ( 0 , -1/2)
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Directrix = -p (standard form),,,,Directrix = - (-1/2),,,or directrix = 1/2
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