Let us consider a uniform spherical shell of mass M. Its mass per unit area will be M/4πR2 = σ. Let us consider a strip of width R dθ and radius R sin θ (see figure). The whole shell is made up of such strips.
The plot V(x) is shown here.At x =R, the plot has a corner where it is not differentiable. The plot of g(x) has a x finite discontinuity at x = R.
