Question 287712: Use the distance formula to find the equation of a parabola with focus F(4,0) and directrix x= -3.
Answer by stanbon(75887) (Show Source):
You can put this solution on YOUR website! Use the distance formula to find the equation of a parabola with focus F(4,0) and directrix x= -3.
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Find the equation relating to all points (x,y)
that are equidistance from (4,0) and (-3,y).
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sqrt[(x-4)^2 + y^2] = sqrt[(x+3)^2 + 0]
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x^2-8x+16 + y^2 = x^2+6x+9
-8x + 16 + y^2 = 6x+9
-14x + y^2 = -7
14x = y^2 + 7
x = (1/14)y^2 + (1/2)
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Cheers,
Stan H.
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