Euler’s formula for cosine

$\cos \omega t = \dfrac{1}{2} (e^{+j\omega t} + e^{-j\omega t})$

Cosine emerges on the real axis, the vector sum of two spinning numbers,

The green spinning number is $+\dfrac{1}{2} e^{+j\omega t}$
The red spinning number is $+\dfrac{1}{2} e^{-j\omega t}$

Cosine (the orange dot) is the vector sum of green and red.

Created by Willy McAllister.

Just music, no narration. The background music is NirvanaVEVO by Chris Zabriskie,
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