ThmDex – An index of mathematical definitions, results, and conjectures.

Formulation F12289 on R5125: Euler's formulas

F12289

Formulation 1

Let $z \in \mathbb{C}$ be a D1207: Complex number.
Let $i$ be the D371: Imaginary number.

Then

(1)	\begin{equation} e^{i z} = \cos z + i \sin z \end{equation}
(2)	\begin{equation} e^{- i z} = \cos z - i \sin z \end{equation}