cos\alpha=\frac{\sqrt{5}}{3}
sin^2\alpha+cos^2x=1
sin^2\alpha=1-(\frac{\sqrt{5}}{3})^2
sin^2\alpha=1-\frac{5}{9}
sin^2\alpha=\frac{4}{9}
sin\alpha=\sqrt{\frac{4}{9} }=\frac{2}{3}
tg\alpha=\frac{sin\alpha}{cos\alpha}=\frac{\frac{2}{3}}{\frac{\sqrt{5}}{3}}=\frac{2}{3}*\frac{3}{\sqrt{5}}=\frac{2}{\sqrt{5}}
ctg\alpha=\frac{1}{tg\alpha}=\frac{1}{\frac{2}{\sqrt{5}}}=\frac{\sqrt{5}}{2}