User:ALonelyPhoenix

It's me! ALonelyPhoenix, most of the time i go around reading math wikipedia articles, and with this account being made perhaps i could start editing some

Welp thats all, cya!

= Contributions = None lol

Cantor's definition of two sets having the same size can be formalized as:

$$ \forall A,B : |A| = |B|  \Longleftrightarrow \exists f:(\forall x \in A: \exists! y \in B :(f(x)=y)) $$

Or in english: Two sets A and B are of equal size if you can make a one-to-one correspondence between each element of the two, or mathematically speaking:

$$ A \xrightarrow{f} B, f \,\,\, \text{biyective}    $$

trigonometry!

$$\sin (-\alpha) = - \sin (\alpha)$$     $$\csc (-\alpha) = - \csc( - \alpha )$$

$$\cos (- \alpha ) = \cos(\alpha)$$         $$\sec (- \alpha) = \sec(\alpha)$$

$$\text{tg} (-\alpha) = - \text{tg} ( \alpha )$$         $$\text{ctg} ( - \alpha) = - \text{ctg} (\alpha )$$