+816 The points (-3,2) and (-2,3) lie on a circle whose center is on the x-axis. What is the radius of the circle?
+128475 Let the center be (x, 0)
The points will be equidistant from the center..so....we can solve this
(x + 3)^2 + (0 - 2)^2 = (x + 2)^2 + (0 - 3)^2 simplify
x^2 + 6x + 9 + 4 = x^2 + 4x + 4 + 9
6x = 4x ⇒ x = 0
So.....the center is (0, 0)
And the radius is sqrt ( (-3 - 0)^2 + ( 2 - 0)^2 ) = sqrt [ 9 + 4 ] = sqrt (13)
