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Question
Find the centre and radius of the circle:
(x − 5)2 + (y − 3)2 = 20
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Solution
Given equation of the circle is
(x − 5)2 + (y − 3)2 = 20
∴ (x − 5)2 + (y − 3)2 = `(sqrt(20))^2`
Comparing this equation with
(x − h)2 + (y − k)2 = r2, we get
h = 5, k = 3 and r = `sqrt(20) = 2sqrt(5)`
∴ Centre of the circle = (h, k) = (5, 3)
and radius of the circle = `2sqrt(5)`.
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