# Trigonometria

| Nome                     | Formula                                                              | Lettere                   |
| ------------------------ | -------------------------------------------------------------------- | ------------------------- |
| Pitagora                 | $i^2=c^2+c^2$                                                        | $i$ ipotenusa, $c$ cateto |
| 1 relazione fondamentale | $\sin^2(\alpha)+\cos^2(\alpha)=1$                                    | $\alpha$ angolo scelto    |
| 2 relazione fondamentale | $\tan(\alpha)=\frac{\sin(\alpha)}{\cos(\alpha)}$                     | $\alpha$ angolo scelto    |
| cotangente               | $\cot(\alpha)=(\tan(\alpha))^{-1}=\frac{\cos(\alpha)}{\sin(\alpha)}$ | $\alpha$ angolo scelto    |
|                          |                                                                      |                           |


| Angolo notevole          | Seno                 | Coseno               | Tangente                                                    |
| ------------------------ | -------------------- | -------------------- | ----------------------------------------------------------- |
| $0°=0rad$                | $0$                  | $1$                  | $\frac{0}{1}=0$                                             |
| $30° = \frac{\pi}{6}rad$ | $\frac{1}{2}$        | $\frac{\sqrt{3}}{2}$ | $\frac{\frac{1}{2}}{\frac{\sqrt{3}}{2}}=\frac{1}{\sqrt{3}}$ |
| $45° = \frac{\pi}{4}rad$ | $\frac{\sqrt{2}}{2}$ | $\frac{\sqrt{2}}{2}$ | $\frac{\frac{\sqrt{2}}{2}}{\frac{\sqrt{2}}{2}}=1$           |
| $60° = \frac{\pi}{6}rad$ | $\frac{\sqrt{3}}{2}$ | $\frac{1}{2}$        | $\frac{\frac{\sqrt{3}}{2}}{\frac{1}{2}}=\sqrt{3}$           |
| $90°=\frac{\pi}{2}rad$   | $1$                  | $0$                  | $\frac{1}{0}$                                               |
| $180°=\pi rad$           | $0$                  | $1$                  | $\frac{0}{1}$                                               |
| $270°=\frac{3\pi}{2}rad$ | $1$                  | $0$                  | $\frac{-1}{0}$                                              |