от Xixibg » 11 Окт 2011, 20:53
[tex]sin\alpha =\frac{a}{c}=\frac{1}{2}[/tex]
[tex]cos\alpha =\sqrt{1-sin^2\alpha }=\sqrt{\frac{3}{4}}=\frac{\sqrt{3}}{2}[/tex]
[tex]sin\beta =cos\alpha =\frac{\sqrt{3}}{2}[/tex]
[tex]cos\beta =sin\alpha =\frac{1}{2}[/tex]
[tex]tg\beta =\frac{sin\beta}{cos\beta }= \frac{\sqrt{3}}{2}:\frac{1}{2}=\frac{\sqrt{3}}{2}.\frac{2}{1}=\sqrt{3}[/tex]
[tex]cotg\beta =\frac{1}{tg\beta }=\frac{\sqrt{3}}{3}[/tex]