Question

4.centre (1,1) and radíus

Answer 1

The given center of circle is ( 1,1 ) and the radius is 2 .

The formula for the equation of circle is given by,

( x−h ) 2 + ( y−k ) 2 = r 2 (1)

Where h and k denotes the center of the circle and r denotes the radius of the circle.

From the question, h=1,k=1 and r= 2

Substitute the values of h, k and r in equation (1), to find the equation of circle.

( x−1 ) 2 + (y−1) 2 =2 x 2 +1−2x+ y 2 +1−2y=2 x 2 + y 2 −2x−2y=2−2 x 2 + y 2 −2x−2y=0

Thus the equation of the circle with center ( 1,1 ) and radius 2 is x 2 + y 2 −2x−2y=0 .