How do you find the center and radius of the circle given $x^2+y^2+2x-10=0$ ?

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Answer 1 · 2018-03-31T10:41:00

centre $C (-1,0) and r=sqrt11$

The general equation of the circle:

$x^2+y^2+2gx+2fy+c=0.......to(I)$ ,

whose centre $C(-g,-f) and$ radius $r=sqrt(g^2+f^2-c)$

We have,

$x^2+y^2+2x-10=0$

Comparing with $(I)$ , we get

$2g=2,2f=0,c=-10$

i.e. $g=1,f=0,c=-10$

So,

centre $C(-1,0) and r=sqrt((1)^2+(0)^2-(-10))=sqrt11$

How do you find the center and radius of the circle given x^2+y^2+2x-10=0x^2+y^2+2x-10=0?