Answer
$(x-1)^2+(y-0)^2=\sqrt{20}$.
Work Step by Step
The general equation for a circle with radius $r$ and centre $(h,k)$ is: $(x-h)^2+(y-k)^2=r^2$.
The distance formula from $P_1(x_1,y_1)$ to $P_2(x_2,y_2)$ is $d=\sqrt{(x_2-x_1)^2+(y_2-y_1)^2}$.
Hence here: $r=\sqrt{(1-(-3))^2+(0-2)^2}=\sqrt{16+4}=\sqrt{20}.$
Also $C=(1,0)$, hence our equation: $(x-1)^2+(y-0)^2=\sqrt{20}$.
