A circle with center C has equation x^2 + y^2 + 8x - 12y = 12
Circle equation = (x - a)2 + (y - b)2 = r2Where Centre coordinates (a, b) and radius 'r'Therefore x2 + y2 + 8x - 12y = 12 is to be rewritten in this formComplete the square to find a and bThis gives(x+4)2 - 16 + (y - 6)2 - 36 = 12Simplify(x+4)2 + (y - 6)2 = 64Therefore refering to the top two linesCentre of the circle is (-4, 6) and Radius of the circle is 8
