Mathematics - Complex Number Question with Solution | TestHub

Let $z=x+iy$ Set $A$ corresponds to the region $y\ge 1$. Set $B$ consists of points lying on the circle, centred at $(2,1)$ and radius 3 , i.e., $x^2+y^2-4x-2y=4$ $$\text{ Set }C\text{ consists of points lying on the }x+y=\sqrt{2}$$
Clearly, there is only one point of intersection of the line $$x+y=\sqrt{2}\text{ and circle }{x}^2+y^2-4x-2y=4.$$