Question

Why phi is between 0 to pi in spherical polar coordinates?

Answer 1

because after 0 1come that's why

Answer 2

Spherical coordinates have 2 angles. It's like a position on earth, which has latitude and longitude. Longitude goes all the way around (total angle 2π). And latitude goes from pole to pole (total angle π). Oh, and welcome to PF! :smile:

Reference https://www.physicsforums.com/threads/in-spherical-coord-system-why-do-we-limit-the-angle-phi-from-zero-to-pi-and-not-2pi.495364/