A popular model for the mass distribution in a spheroid (such as a bulge) is the
Hernquist model, with density
ρ(r) = M(total)*a / 2πr(a+r)^3
M(total) is the total mass. a is constant with dimensions of length. Derive the enclosed mass
The Attempt at a Solution
I am completely unsure on how to go about doing this? Any help is appreciated!