The equations of the tangents to the circle $x^2+y^2=4$ drawn from the point $(4,0)$ are

The image of every point lying on the curve $x^2+y^2=1$ in the line $x+y=1$ satisfies the equation

If the inverse of $P(-3,5)$ with respect to a circle is $(1,3)$ then polar of $P$ with respect to that circle is

If the tangent drawn at the point $P$ on the circle $x^2+y^2+6 x+6 y=2$ meets the straight line $5 x-2 y+6=0$ at a point $Q$ on the $Y$-axis, then the length of $P Q$ is