5 π 6 ⇒ ( − 3 2 , 1 2 ) {\displaystyle {\frac {5\pi }{6}}\Rightarrow \left({\frac {-{\sqrt {3}}}{2}},{\frac {1}{2}}\right)}
sin ( 5 π 6 ) = 1 2 csc ( 5 π 6 ) = 2 1 = 2 cos ( 5 π 6 ) = − 3 2 sec ( 5 π 6 ) = 2 − 3 ⋅ 3 3 = − 2 3 3 tan ( 5 π 6 ) = 1 2 − 3 2 = ( 1 2 ) ( − 2 3 ) = − 1 3 ⋅ 3 3 = − 3 3 cot ( 5 π 6 ) = − 3 1 = − 3 {\displaystyle {\begin{aligned}\sin {\left({\frac {5\pi }{6}}\right)}&={\frac {1}{2}}&\csc {\left({\frac {5\pi }{6}}\right)}&={\frac {2}{1}}=2\\[2ex]\cos {\left({\frac {5\pi }{6}}\right)}&={\frac {-{\sqrt {3}}}{2}}&\sec {\left({\frac {5\pi }{6}}\right)}&={\frac {2}{-{\sqrt {3}}}}\cdot {\frac {\sqrt {3}}{\sqrt {3}}}=-{\frac {2{\sqrt {3}}}{3}}\\[2ex]\tan {\left({\frac {5\pi }{6}}\right)}&={\frac {\frac {1}{2}}{-{\frac {\sqrt {3}}{2}}}}=\left({\frac {1}{2}}\right)\left(-{\frac {2}{\sqrt {3}}}\right)=-{\frac {1}{\sqrt {3}}}\cdot {\frac {\sqrt {3}}{\sqrt {3}}}=-{\frac {\sqrt {3}}{3}}&\cot {\left({\frac {5\pi }{6}}\right)}&=-{\frac {\sqrt {3}}{1}}=-{\sqrt {3}}\\[2ex]\end{aligned}}}