Definition of de Moivre's theorem in US English:

de Moivre's theorem

  • A theorem which states that (cos θ + i sin θ)ⁿ = cos nθ + i sin nθ, where i is the square root of −1.

    • ‘The de Moivre's theorem is used very often in electrical engineering and physics to determine things like the phase shifts of alternating currents.’


Early 18th century: named after Abraham de Moivre (1667–1754), French-born mathematician, fellow of the Royal Society.


de Moivre's theorem

/də ˈmwävrəz ˌTHirəm/