Q29 of 63 Page 202

Find the equation of the set of all points the sum of whose distances from the points (3, 0) and (9, 0) is 12.

It is given that the sum of the distances from the point (3,0) and (9,0) is 12.


Let the point be (x, y)


Distance between the point of intersection & centre = [Distance Formula]





Squaring both the sides,





Squaring both the sides,



x2 + 12x + 36 = 4x2 - 24x + 36 + 4y + 2


3x2 - 36x + 4y2=0
Hence, the required equation is 3x2 - 36x + 4y2 = 0.


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