The equation $x^2+y^2=0$ denotes

Q. The equation $x^2+y^2=0$ denotes

Q. Assertion :The equation of the circle passing through the point $(2a,0)$ and whose radical axis is $x=\frac{a}{2}$ with respect to the circle $x^2+y^2=a^2$, will be $x^2+y^2-2ax=0$ Reason: The equation of radical axis of two circles $x^2+y^2+2g_{1}x+2f_{1}y+c_1=0$ and $x^2+y^2+2g_{2}x+2f_{2}y+c_2=0$ is $2(g_1-g_2)x+2(f_1-f_2)y+(c_1-c_2)=0$

Q. Circle $x^2+y^2+6y=0$ touches

Q. The equation of a circle whose radius is $8$ units and which touches both $x-$axis and $y-$axis is

Q. Find the equation of the circle passing through point of intersection of the circle $x^2+y^2-8x-2y+7=0$ and $x^2+y^2-4x+10y+8=0$ and its center lie on y-axis.