# Euler formulas

Formulas connecting the exponential and trigonometric functions:

These hold for all values of the complex variable . In particular, for a real value the Euler formulas become

#### References

 [1] L. Euler, Miscellanea Berolinensia , 7 (1743) pp. 193–242 [2] L. Euler, "Einleitung in die Analysis des Unendlichen" , Springer (1983) (Translated from Latin) [3] A.I. Markushevich, "A short course on the theory of analytic functions" , Moscow (1978) (In Russian)