| 1 | ||
Dany jest kwadrat abcd. Na boku BC obrano punkt E taki że |BE|= | |BC|. Cosinus kąta EAB | |
| 3 |
| 3√10 | ||
A. | ||
| 10 |
| √10 | ||
B. | ||
| 10 |
| √3 | ||
C. | ||
| 2 |
| √3 | ||
D. | ||
| 6 |
Przepraszam za rysunek, pierwszy raz używam tego xD To a na różowo to α
| a | ||
cosα = | ||
| x |
| a | ||
x2 = a2 + ( | )2 | |
| 3 |
| a2 | ||
x2 = a2 + | ||
| 9 |
| 10a2 | ||
x2 = | / √ ,x>0 | |
| 9 |
| a √10 | ||
x = | ||
| 3 |
| a | 3 | 3 | 3 √10 | |||||||||||
cosα = | = a * | = | = | |||||||||||
| a √10 | p {10} | 10 |