Sine of Zero is Zero

Theorem

 * $\sin 0 = 0$

where $\sin$ denotes the sine.

Proof
Recall the definition of the sine function:


 * $\displaystyle \sin x = \sum_{n \mathop = 0}^\infty \left({-1}\right)^n \frac {x^{2n+1}}{\left({2n+1}\right)!} = x - \frac {x^3} {3!} + \frac {x^5} {5!} - \cdots$

Thus:
 * $\displaystyle \sin 0 = 0 - \frac {0^3} {3!} + \frac {0^5} {5!} - \cdots = 0$

Also see

 * Cosine of Zero is One