# In the (x, y) coordinate plane, what is the radius of the circle described by the equation (x - 3)^2 + (y + 6)^2=sqrt15?

The given equation is the equation of a circle with center at $\left(3 , - 6\right)$ and radius $\sqrt[4]{15} = 1.968$.
It is apparent from the equation's LHS that the square of distance of the point $\left(x , y\right)$ from $\left(3 , - 6\right)$ is always $\sqrt{15}$ (on the RHS).
Hence, the given equation is the equation of a circle with center at $\left(3 , - 6\right)$ and radius $\sqrt{\sqrt{15}}$ or $\sqrt[4]{15} = 1.968$.