Find the standard form of the eqation of a circle whose center is at (2,5) and whose radius is 4.
The standard form of the equation of a circle whose center is (h, k) and whose radius is r is:
(x - h)2 + (y - k)2 = r2
Since the center is (2, 5), h = 2 and k = 5; since the radius is 4, r = 4:
(x - 2)2 + (y - 5)2 = 42 or (x - 2)2 + (y - 5)2 = 16
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