| 3 | ||
cos2x = 2cos2x − 1 = | ||
| 4 |
| 7 | ||
2cos2x = | ||
| 4 |
| 7 | ||
cos2x = | ||
| 8 |
| √7 | √7 | |||
cosx = | lub cosx = − | (wybieram dodatniego cosx) | ||
| √8 | √8 |
| √7 | 7 | 1 | ||||
sin2x = 1 − ( | )2 = 1 − | = | ||||
| √8 | 8 | 8 |
| 1 | 1 | |||
sinx = | lub sinx = − | (wybieram dodatniego sinx) | ||
| √8 | √8 |
| sinx | 1 | √8 | 1 | |||||
tgx = | = | * | = | |||||
| cosx | √8 | √7 | √7 |
