<PRE><B>Question 863824</B>
The centre of a circle lies on the x-axis and passes through the points (4,5) and (-2,3). Find the equation of the circle in the form x^2+y^2+2gx+2fy+c=0
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Plot the points; let the center be (x,0)
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Radii are equal::
sqrt[(4-x)^2 + (5-0)^2] = sqrt[(-2-x)^2+(3-0)^2]
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(4-x)^2 + 5^2 = (2+x)^2+9
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16-8x+x^2 + 25 = 4 + 4x + x^2 + 9
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41 - 6x = 13+4x
10x = 28
x = 2.8
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Center is (2.8,0)
radius = sqrt[(4-2.8)^2 + 25] = sqrt[1.44+ 25] = sqrt(26.44)
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Equation:
(x-2.8)^2 + y^2 = 26.44
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Cheers,
Stan H.
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