\sin\alpha=\frac{15}{17}
\sin^2\alpha+\cos^2\alpha=1
\cos^2\alpha=1-\sin^2\alpha=1-(\frac{15}{17})^2=1-\frac{225}{289}=\frac{64}{289}
\cos\alpha=\sqrt{\frac{64}{289}}=\frac{8}{17} lub \cos\alpha=-\frac{8}{17}
\tan\alpha=\frac{\sin\alpha}{\cos\alpha}=\frac{\frac{15}{17}}{\frac{8}{17}}=\frac{15}{17}*\frac{17}{8}=\frac{15}{8}
lub
\tan\alpha=\frac{\sin\alpha}{\cos\alpha}=\frac{\frac{15}{17}}{-\frac{8}{17}}=\frac{15}{17}*(-\frac{17}{8})=-\frac{15}{8}
\cot\alpha=\frac{1}{\tan\alpha}=\frac{8}{15}
lub
\cot\alpha=\frac{1}{\tan\alpha}=-\frac{8}{15}