3 | ||
oblicz wartość wyrażenia sinαcosβ − cosαsinβ, jeśli tgα= | , ctgβ=1 | |
4 |
1 | ||
ctgβ=1 stąd | =tgβ=1 stąd β=45o | |
ctgβ |
√2 | √2 | |||
więc sinβ= | i cosβ= | |||
2 | 2 |
3 | ||
Teraz tgα= | ||
4 |
tgα | (3/4) | 3 | ||||
sinα= | = | =(3/4)/(5/4)= | ||||
√1+tg2α | √1+916 | 5 |
1 | 4 | |||
cosα= | = (1)/(5/4)= | |||
√1+tg2α | 5 |
3 | √2 | 4 | √2 | |||||
sinα*cosβ−cosα*sinβ= | * | − | * | = | ||||
5 | 2 | 5 | 2 |
3√2 | 4√2 | √2 | |||
− | = − | ||||
10 | 10 | 10 |