10. Abraham de Moivre (1667-1754) left France to seek religious refuge in London at eighteen
years of age. There he befriended Newton. In 1698 he mentions that Newton knew, as
early as 1676 of an equivalent expression to what is today known as de Moivre’s theorem:
(cos(θ) + i sin(θ))n = cos(nθ) + i sin(nθ)
where n is an integer. Apparently Newton used this formula to compute the cubic roots
that appear in Cardan formulas, in the irreducible case. de Moivre knew and used the
formula that bears his name, as it is clear from his writings -although he did not write it
out explicitly.