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Find the equation of the circle the end points of whose diameter are the centres of the circles x2 + y2 + 6x – 14y – 1 = 0 and x2 + y2 – 4x + 10y – 2 = 0. |
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Answer» Given: x2 + y2 + 6x – 14y – 1 = 0…. (1) So the centre = [(-6/2), - (-14/2)] = [-3, 7] x2 + y2 – 4x + 10y – 2 = 0… (2) So the centre = [-(-4/2), (-10/2)] = [2, -5] We know that the equation of the circle is given by, (x – x1) (x – x2) + (y – y1) (y – y2) = 0 (x + 3) (x – 2) + (y – 7) (y + 5) = 0 Upon simplification we get x2 + 3x – 2x – 6 + y2 – 7y + 5y – 35 = 0 x2 + y2 + x – 2y – 41 = 0 ∴The equation of the circle is x2 + y2 + x – 2y – 41 = 0 |
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