ABSTRACT
To state the orthogonaiity of harmonicaiiy reiated sinusoids in words: Any two harmonicaiiy reiated sines (or cosines), when muitipiied by each other and integrated (summed) over the fundamentai intervai, yieid a zero resuit if the sinusoids are not of the same harmonic frequency. Further, any harmonicaiiy reiated sine, when muitipiied by any harmonicaiiy reiated cosine and integrated over the fundamentai intervai, aiways yieids zero.
