>>16835519
>muh quantum
OP is taking an E&M class and Legendre polynomials appear in even the most
trivial classical E&M problems, like a point charge off the center of your coordinate system which takes the form
[eqn] \Phi(r) = \frac{q}{4\pi \varepsilon_0}\frac{1}{\sqrt{r^2+a^2-2ar\cos\theta}}=\frac{q}{4\pi \varepsilon_0 r} \sum_{m=0}^\infty \left(\frac{a}{r}\right)^m P_m(\cos \theta) [/eqn]

How has nobody on this board taken a basic antenna class?