Equation of a circle with a center that passes through a point

Question

Write the equation of the circle with center at (-1,3) and passes through the point (2,-4).

Answer 1

the distance between the center and any point on the circle is the diameter of it so :

$r = \sqrt{(2-(-1))^2+(-4-3)^2} = $

then your equation is

$(x-x_0)^2 + (y-y_0)^2=r^2$

$(x+1)^2+(y-3)^2=r^2$