| sinα | ||
tgα= | ||
| cosα |
| 1 | ||
ctgα= | ||
| tgα |
| 1 | ||
ctgα= | ||
| 4 |
| 1 | sinα | ||
= | |||
| 4 | cosα |
| √17 | √17 | |||
sinα= | lub sinα=− | |||
| 17 | 17 |
| √17 | 4√17 | |||
cosα=4 | = | lub | ||
| 17 | 17 |
| −√17 | −4√17 | |||
cosα=4 | = | |||
| 17 | 17 |
2 sposób: ( polecam 
dla kątów ostrych:
a=4x b= x dla x>0
| a | 4x | |||
tgα= 4= | = | |||
| b | x |
| a | 4x | 4 | 4√17 | |||||
sinα= | = | = | = | |||||
| c | √17 x | √17 | 17 |
| b | x | 1 | √17 | |||||
cosα= | = | = | = | |||||
| c | √17 x | √17 | 17 |
Wartości ujemne odzrzucamy , bo kąt α −−− ostry