What is the general form of the equation of a circle with its center at (-2, 1) and passing through (-4, 1)?

Question

freckles · Answer

An equation for a circle with center (h,k) and radius r is:
$$(x-h)^2+(y-k)^2=r^2$$
so plug in your h and k

freckles · Answer

then use the point on (-4,1) to plug into (x,y) since (-4,1) is on the circle
to find r

usukidoll · Answer

don't we also have (h,k) for the center ?

freckles · Answer

yep that is the first step
"plug in your h and k"

usukidoll · Answer

so since we have (-2,1) in the form of (h,k) we let h =-2, and k = 1

freckles · Answer

yes that is the h and k
since my center of my equation I have above is (h,k)
and the center of his is (-2,1)
so yep he needs to replace h with -2 and k with 1