The familiar formula know by De Moivre’s name and found in every theory of equations text book, was familiar to De Moivre for the case where n is a positive integer. This formula has become the keystone of analytic trigonometry Rather interesting is the fable often told of De Moivre’s drath. According to the story De Moivre noticed that each day he required a quarter of an hour more sleep than on the preceding day.