If the points A(4, 3) and B(x, 5) lie on the circle with centre 0(2, 3), find the value of x.
The distance of any point which lies on the circumference of the circle from the centre of the circle is called radius.
∴ OA = OB = Radius of given Circle
taking square on both sides, we get-
OA2 = OB2
⇒ (2-4)2 + (3-3)2 = (2-x)2 + (3-5)2
[using distance formula, the distance between points (x1,y1) and (x2,y2) is equal to 
units.]
⇒ (-2)2 + 0 = x2-4x + 4 + (-2)2
⇒ x2-4x + 4 = 0
⇒ (x-2)2 = 0
∴ x = 2
Thus, the value of x is 2.
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