Question 603659
Hi, I'm having a hard time understanding how to do the equation conversion of given points on a parabola like the focus and vertex into an equation. 
The given points are: 
vertex (8,6)/ Focus (8,1)
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Plot the 2 points and you will see the parabola must be opening downward
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Form:
(x-h)^2 = 4p(y-k)
h = 8 ; k = 6
p = 1-6 = -5
4p = -20
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Equation:
(x-8)^2 = -20(y-6)
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x^2-16x+64 = -20y+120
20y = -x^2+16x+54
y = (-1/20)x^2+(4/5)x+2.7
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{{{graph(400,400,-10,20,-10,10,(-1/20)x^2+(4/5)x+2.7)}}}
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Cheers,
Stan H.