Fourier Series The strings:

S7P5A51 (Physical Change)

The math: Pj Problem of Interest is of type change. Fourier series basically replaces a periodic function with an infinite sum of sinusoids. It is in this sense that it is a change problem. The importance of the Fourier series is that periodic functions or functions defined on finite intervals can be represented by infinite series of sines and cosines. The orthogonality of the sin and cosine functions indicated in the expressions for the Fourier coefficients, simplifies the determination of the coefficients.

Each term in the Fourier series is called the harmonic. Each harmonic has a larger frequency than the preceeding term, and all frequencies are multiples of a fundamental frequency that has the same period as that of the function f(x) represented by the Fourier series.

Math The Universe is composed of matter and radiant energy. Matter is any kind of mass-energy that moves with velocities less than the velocity of light. Radiant energy is any kind of mass-energy that moves with the velocity of light.
Periodic Table
Composition And Structure Of Matter
How Matter Gets Composed
How Matter Gets Composed (2)
Molecular Structure Of Matter
Molecular Shapes: Bond Length, Bond Angle
Molecular Shapes: Valence Shell Electron Pair Repulsion
Molecular Shapes: Orbital Hybridization
Molecular Shapes: Sigma Bonds Pi Bonds
Molecular Shapes: Non ABn Molecules
Molecular Orbital Theory
More Pj Problem Strings

Blessed are they that have not seen, and yet have believed. John 20:29