| 1 | ||
Oblicz: sin(arctg5 − arccos | ) | |
| 5 |
| π | π | |||
arctg(5)=α, α∊(− | , | , wtedy: | ||
| 2 | 2 |
| 1 | 1 | π | ||||
arccos( | )=β , β∊<0,π>⇔cosβ= | ⇒β∊(0, | ) | |||
| 5 | 5 | 2 |
| 1 | ||
sin2β=1− | ||
| 25 |
| √24 | ||
sinβ= | ||
| 5 |
| sinα | |
=5⇔sinα=5cosα | |
| cosα |
| 1 | √26 | |||
cosα= | = | |||
| √26 | 26 |
| 5√26 | ||
sinα= | ||
| 26 |
| 5√26 | 1 | √24 | √26 | |||||
sin(α−β)= | * | − | * | = | ||||
| 26 | 5 | 5 | 26 |
| √26*(5−2√6) | ||
= | ||
| 5*26 |