# the centre of a circle is (2a,a-7) using distance formula find the values of 'a' if the circle passes through the point (11,-9),and has the diameter 10 root 2 units

Dear student,

length of the diameter =

therefore the radius r =

let the center of the circle be C .

let it passes through the point P(11,-9).

therefore PC= r

therefore a=3 or a=5.

hence the center of the circle is

i.e. the center of the circle is (6,-4) or (10,-2).

Regards

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