The generic equation of the circle is: (x-xo) ^ 2 + (y-yo) ^ 2 = r ^ 2 The first thing we must see for this case is where the circle is centered. We note that the circle is centered on the following ordered pair: (xo, yo) = (-1, -3). We now observe the radius of the circle: The diameter is: d = l-5 - (- 1) l d = 4 the radio will be: r = d / 2 = 4/2 = 2 r = 2 Substituting values: (x - (- 1)) ^ 2 + (y - (- 3)) ^ 2 = (2) ^ 2 Rewriting: (x + 1) ^ 2 + (y + 3) ^ 2 = 4 Answer: The equation of the circle is: (x + 1) ^ 2 + (y + 3) ^ 2 = 4 option 3
