Euler's Formula/Examples/e^i pi by 4

Example of Use of Euler's Formula

$e^{i \pi / 4} = \dfrac {1 + i} {\sqrt 2}$


Proof

\(\ds e^{i \pi / 4}\) \(=\) \(\ds \cos \frac \pi 4 + i \sin \frac \pi 4\) Euler's Formula
\(\ds \) \(=\) \(\ds \dfrac {\sqrt 2} 2 + i \dfrac {\sqrt 2} 2\) Cosine of $\dfrac \pi 4$, Sine of $\dfrac \pi 4$
\(\ds \) \(=\) \(\ds \dfrac {1 + i} {\sqrt 2}\) simplification

$\blacksquare$


Sources

  • 1960: Walter Ledermann: Complex Numbers ... (previous) ... (next): $\S 2$. Geometrical Representations: $(2.19)$