Question

Graph the circle with center at (-1, -2), which also passes through the point (0, 2). Label the center and at least four points on the circle. Write the equation of the circle.

Answer 1

Circle of equation with center (h,k): \(\large (x-h)^2+(y-k)^2=1\)

Answer 2

Another way of looking at this is that the distance from the center of a circle to any point on the circle is the radius, and it's fixed. So, you calculate the distance between the center and the radius using the euclidean distance formula:
\[\sqrt{(x_2-x_1)^2+(y_2-y_1)^2}\]. From there, you can plot 4 additional points from your center by just going up, down, left, and right from the center that many units.
(hint, when you use that distance formula, you'll get a whole number)