I have the following problem: Let $\phi$ be a 2-form in $\mathbb{R}^3/{0}$ with $$\phi=\frac{1}{(x^2+y^2+z^2)^{\frac{3}{2}}}(xdy\wedge dz+ydz\wedge dx+zdx\wedge dy)$$ Calculatate $\int_{S^2}\phi$ with the Stokes theorem.
Here I have the problem that $\phi$ is not defined for $(0,0,0)$. Can someone explain how to use the theorem on this problem? Thanks in advance.