Question

Find the equation of the circle with center at
(-2,1)
and passes through the point
(3,1)
.

Answer 1

Radius (R) is equal to the distance between the points (-2,1) and (3,1)
R² = (-2 - 3)² + (1 - 1)² = (-5)² + 0 = 25
R = 5 

Equation of the circle:
(х-(-2))² + (у-1)² = 5²
(х+2)² + (у-1)² = 25