Euler's Formula/Examples/e^i pi by 2

Example of Use of Euler's Formula

$e^{i \pi / 2} = i$


Proof

\(\ds e^{i \pi / 2}\) \(=\) \(\ds \cos \frac \pi 2 + i \sin \frac \pi 2\) Euler's Formula
\(\ds \) \(=\) \(\ds 0 + i \times 1\) Cosine of $\dfrac \pi 2$, Sine of $\dfrac \pi 2$
\(\ds \) \(=\) \(\ds i\)

$\blacksquare$


Sources

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