Đâu là mô tả đúng của công thức Euler A. e j ω n = j c o s ω n + s i n ω n

$\text{e}{}^{j\omega n}=j\text{c}\text{o}\text{s}\omega n+\text{s}\text{i}\text{n}\omega n$

$\text{e}{}^{j\omega n}=\text{c}\text{o}\text{s}\omega \text{n}-j\text{s}\text{i}\text{n}\omega \text{n}$

$\text{e}{}^{j\omega n}=j\text{c}\text{o}\text{s}\omega \text{n}-\text{s}\text{i}\text{n}\omega \text{n}$

$\text{e}{}^{j\omega n}=\text{c}\text{o}\text{s}\omega n+\text{j}\cdot \text{s}\text{i}\text{n}\omega n$