 Complementary series representation

Complementary series representation is a concept in mathematics and physics, especially in the context of wave functions and solutions to differential equations. The term is often associated with Legendre functions, spherical harmonics, and other orthogonal function systems where two series representations can complement each other to form a complete solution. Here's a more detailed explanation: ### 1. **In Mathematics**: - In certain contexts, functions can be expressed in terms of two series that together provide a full representation of the function.