imaginary circle

imaginary circle

[i¦maj·ə‚ner·ē ′sər·kəl] (mathematics) The set of points in the x-y plane that satisfy the equation x 2+ y 2= -r 2, or (x - h)2+ (y - k)2= -r 2, where r is greater than zero, and x, y, h, and k are allowed to be complex numbers.