find the coordinates for the center of a circle with a diameter having endpoints at (0,2) and (-9,-2)

(x−2)2+(y+1)2=100

Explanation:

the standard form of the equation of a circle is  

2 2 ( x − a ) 2 + ( y − b ) 2 = r 2 2 2  where  ( a , b )  are the coordinates of the center and r is  the radius  to find the center we require the  midpoint of the  2 given points  center  = [ 1 2 ( − 4+ 8 ) , 1 2 ( 7 − 9 ) ]  center = ( 2 , − 1 )  the radius is the distance from the center to either of  the 2 given points  calculate the radius using the  distance formula ∙  d = √ ( x2 − x 1 ) 2 + ( y 2 − y 1 ) 2  let  ( x 1 , y 1) = ( 2 , -1 )  and  ( x 2 , y 2 ) = ( − 4 , 7 ) r = √ = √ ( − 4 − 2 ) 2 + ( 7 + 1 ) 2 = √ 36 + 64 = 10 ⇒ ( x − 2 ) 2 + ( y − ( − 1 ) ) 2 = 10 2 ⇒ ( x − 2 )2 + ( y + 1 ) 2 = 100 ←  equation of circle