Is the Quadrupole Moment Non-Zero?

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Homework Statement
Given ##\rho=(k/r)sin(\theta)cos(\phi)## for a sphere of radius R, find the lowest non-vanishing multipole moment.
Relevant Equations
General multipole expansion equation, as well as spherical harmonics (I think).
I have been throwing everything I can at this. I believe that both the monopole and dipole are zero, but I have no clue as to how to evaluate the quadrupole moment.
 
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What is the formula to calculate the quadrupole moment?
 
If I did it right, the dipole moment has one non-zero component.
 
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