Delta-K,  Feature Articles,  Volume 7, Issue 1

TRIGONOMETRIC FUNCTIONS OF SUMS

Journal of the Mathematics Council of the Alberta Teachers’ Association

Volume 7 Issue 1, December 1967

2 – 3

TRIGONOMETRIC FUNCTIONS OF SUMS

William J. Bruce

The following analytic method of launching a study of trigonometric functions of sums involves the unit circle, the distance formula and a simple rotation; it also furnishes quite briefly a completely general result in a rather elegant manner.