The inverse point of (1, -1) with respect to x2+y2=4, is

We know that two points are inverse points with respect to a circle if each lies on the polar of the other. The polar of (1, -1) with respect to x2+y2=4 is  x-y=4Clearly, (2, - 2) lies on it. Hence, the inverse point of (1, -1) with respect of x2+y2=4 is  (1,-1).