find an equation of the circle that has center (-2,2) and passes through (1,-4)

Answer 1

The equation of a circle is (x-h)^2 + (y-k)^2 = r^2

We are given that (h,k) = -2, 2 and that the circle passes through (x,y) = (1,-4).

Substitute h, k, x and y in to the above equation to get r^2.

The equation of the circle will be (x+2)^2 + (y-2)^2 = r^2 (that you have computed)