👉 Polyharmonic is a mathematical concept that refers to a function of multiple variables, where each variable appears as an exponent or power of another variable. This concept is particularly useful in physics and engineering when dealing with waves, sound, and other complex phenomena involving multiple harmonics. In the context of polyharmonic functions, a single harmonic can be defined as a specific value (a constant) that occurs at every point within the function. Polyharmonic functions are often used to model natural frequencies or oscill