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 |