Trig identities via complex numbers. Chris Tisdell UNSW Sydney

I discuss a simple example illustrating how to obtain trigonometrical identities via complex numbers. In particular, the method involves relationships between sin, cos and the exponential. Such ideas are seen in high-school and first-year university mathematics.

The relationship between $\cos \theta$, $\sin \theta$ and $e^{i\theta}$ and resulting trig simplifications can be more easily worked with, for example, in integration.