textbook-theory · English
Difference Equations to Differential Equations — Section 2.2: Trigonometric Functions
Section 2.2 of Dan Sloughter's open calculus text introduces trigonometric functions from right-triangle and unit-circle definitions, then develops amplitude, period, and phase-angle properties of sine and cosine. The section connects periodic functions to natural phenomena such as pendulum motion and sound waves, and closes with a brief introduction to Fourier series as sums of sine and cosine terms.
trigonometric functionsperiodic functionsFourier seriescalculus