\({\cos ^2}\alpha = 1 - {\sin ^2}\alpha = \dfrac{3}{4}\) nên \(\cos \alpha = \dfrac{{\sqrt 3 }}{2}\)
\(tg\alpha = \dfrac{{\sin \alpha }}{{\cos \alpha }} =\dfrac{{\dfrac{1}{2}}}{{\dfrac{{\sqrt 3 }}{2}}} = \dfrac{1}{{\sqrt 3 }} = \dfrac{{\sqrt 3 }}{3}\)
\(\cot g\alpha = \dfrac{1}{{tg\alpha }} = \sqrt {3.} \)
