dł. AB = 6 dł. AC = 2P{10}
oblicz
tgα * √1−cos2γ +sinα
z góry dziękuję
| |BC| | 2 | |||
sinα= | = | = U{1}{√10 | ||
| |AC| | 2√10 |
| |BC| | 2 | 1 | ||||
tgα = | = | = | ||||
| |AB| | 6 | 3 |
| 1 | ||
cosγ = cos(90o−α)=sinα= | ||
| √10 |
| 1 | 1 | |||
cos2γ=sin2α=( | )2= | |||
| √10 | 10 |
| 1 | 1 | |||
tgα * √1−cos2γ + sinα = | * √1−110 + | = ... dokończ | ||
| 3 | √10 |
x>0 z tw. Pitagorasa x2= (2√10)2−62 ⇒ x2= 4 ⇒ x=2
| sinα | ||
teraz : cosγ= sinα to 1−sin2α= cos2α i tgα= | ||
| cosα |
| sinα | ||
i mamy: tgα*√1−cos2γ+sinα= | *cosα+sinα= sinα+sinα= 2sinα | |
| cosα |
| 2 | √10 | |||
sinα= | = | |||
| 2√10 | 10 |
| √10 | ||
to 2sinα= | ||
| 5 |
| √10 | ||
ładnie wychodzi | ![]() | |
| 2 |
| √10 | |
| 5 |