You are viewing a single comment's thread from:
RE: Ask a Mathematician - therapy for the fear of math or just answers to questions that bug you!
What do you mean "a use"? It is an identity. It has a conceptual beauty as it combines arithmetic, complex numbers, trigonometry and logarithms into one framework.
The general formula e^iz = cosz +isinz is used as the starting point to solve many differential equations.