Question

The circle has center at point (2, 5) and with radius 3, what is the equation of a circle?

Answer 1

Hi friend here is your answer.

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Let equation of the circle be --->

---> x^2+y^2+2gx+2fy+c=0

If centre is 2,5

then -g=2 and -f=5

So g=-2 and f=-5

So x^2+y^2-4x-10y+c=0

And radius = 3 = root g^2+f^2-c

So, 25+4-c= 9

c = 25-9+4 = 25-5 = 20

Hence equation---

x^2+y^2-4x-10y+20=0

ANS.

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