Multipole expansions, calculating the various moments of point charges

[milkism]

Homework Statement

Calculate the mono-di and quadrupole moments of the three charges.

Relevant Equations

See solution.

Problem:

Solution:

This was quite simple, are my solutions correct?

 

[TSny]

Looks very good to me.

 

[PhDeezNutz]

I love your explanations and motivations. Very thorough.