Question 548104: 9. A circle has a radius of 5 units, centre on the line y-2=0 and passes through the point (2,-1). Find the two possible coordinates of the centre of the circle and the respective equations of the circles.
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! A circle has a radius of 5 units, centred on the line y-2=0 and passes through the point (2,-1). Find the two possible coordinates of the center of the circle and the respective equations of the circles.
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Center at (x,2); passing thru (2,-1) with radius = 5 units
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5 = sqrt[(x-2)^2+(2--1)^2]
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25 = x^2-4x+4+9
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x^2-4x-12 = 0
(x-6)(x+2) = 0
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x = 6 or x = -2
Possible coordinates are (6,2) and (-2,2)
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Cheers,
Stan H.
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