Class 11

Math

3D Geometry

Conic Sections

Find the equation of the circle with centre $(1,1)$ and radius $2 $

**Solution: **Here it is given that centre $(h,k)=(1,1)$ and radius $r=2 $

Therefore the equation of the circle is

$(x−1)_{2}+(y−1)_{2}=(2 )_{2}$

$⇒x_{2}−2x+1+y_{2}−2y+1=2$

$⇒x_{2}+y_{2}−2x−2y=0$