Find the equation of the circle concentric with
x2+y2−4x−6y−3=0
and which touches the y-axis.
The given equation of circle is
x2+y2−4x−6y−3=0 …(i)
∴ centre is (−g,−f)=(2,3)
The required circle is concentric with (i)
so, they have same centre = (2, 3)
Also, the required circle touches y - axis at A
∴ CA = radius = 2
∴ equation of circle is
(x−2)2+(y−3)2=4
⇒x2+y2−4x−6y+9=0