Graphical determination of the Fourier series coefficients
William H. Middendorf · Transactions of the American Institute of Electrical Engineers Part I Communication and Electronics · 1956
ALMOST all of the many good textbooks on analysis of electric circuits include analysis of nonsinusoidal waves. Equations are usually given which determine the amplitude of each term of the Fourier trigonometric series. If the dependent variable can be expressed in terms of the independent variable, the familiar relations