210 ⇒ ( 7 π 6 ) ⇒ ( − 3 2 , − 1 2 ) {\displaystyle 210\Rightarrow ({\frac {7\pi }{6}})\Rightarrow ({\frac {-{\sqrt {3}}}{2}},{\frac {-1}{2}})}
sin ( 7 π 6 ) = − 1 2 csc ( 7 π 6 ) = 1 − 1 2 ⋅ 2 = 2 − 1 = − 2 cos ( 7 π 6 ) = − 3 2 sec ( 7 π 6 ) = 1 − 3 2 ⋅ 2 = 2 − 3 ⋅ − 3 = 2 − 3 3 tan ( 7 π 6 ) = − 3 2 − 1 2 ⋅ 2 = − 3 1 = − 3 cot ( 7 π 6 ) = − 3 2 − 1 2 ⋅ 2 = − 3 1 {\displaystyle {\begin{aligned}\sin {\left({\frac {7\pi }{6}}\right)}&={\frac {-1}{2}}&\csc {\left({\frac {7\pi }{6}}\right)}&={\frac {1}{\frac {-1}{2}}}\cdot {2}={\frac {2}{-1}}=-2\\[2ex]\cos {\left({\frac {7\pi }{6}}\right)}&={\frac {-{\sqrt {3}}}{2}}&\sec {\left({\frac {7\pi }{6}}\right)}&={\frac {1}{\frac {-{\sqrt {3}}}{2}}}\cdot {2}={\frac {2}{-{\sqrt {3}}}}\cdot {-{\sqrt {3}}}={\frac {2-{\sqrt {3}}}{3}}\\[2ex]\tan {\left({\frac {7\pi }{6}}\right)}&={\frac {\frac {-{\sqrt {3}}}{2}}{\frac {-1}{2}}}\cdot {2}=-{\frac {\sqrt {3}}{1}}=-{\sqrt {3}}&\cot {\left({\frac {7\pi }{6}}\right)}&={\frac {\frac {-{\sqrt {3}}}{2}}{\frac {-1}{2}}}\cdot {2}=-{\frac {\sqrt {3}}{1}}\\[2ex]\end{aligned}}}
![{\displaystyle {\begin{aligned}\sin {\left({\frac {7\pi }{6}}\right)}&={\frac {-1}{2}}&\csc {\left({\frac {7\pi }{6}}\right)}&={\frac {1}{\frac {-1}{2}}}\cdot {2}={\frac {2}{-1}}=-2\\[2ex]\cos {\left({\frac {7\pi }{6}}\right)}&={\frac {-{\sqrt {3}}}{2}}&\sec {\left({\frac {7\pi }{6}}\right)}&={\frac {1}{\frac {-{\sqrt {3}}}{2}}}\cdot {2}={\frac {2}{-{\sqrt {3}}}}\cdot {-{\sqrt {3}}}={\frac {2-{\sqrt {3}}}{3}}\\[2ex]\tan {\left({\frac {7\pi }{6}}\right)}&={\frac {\frac {-{\sqrt {3}}}{2}}{\frac {-1}{2}}}\cdot {2}=-{\frac {\sqrt {3}}{1}}=-{\sqrt {3}}&\cot {\left({\frac {7\pi }{6}}\right)}&={\frac {\frac {-{\sqrt {3}}}{2}}{\frac {-1}{2}}}\cdot {2}=-{\frac {\sqrt {3}}{1}}\\[2ex]\end{aligned}}}](https://en.wikipedia.org/api/rest_v1/media/math/render/svg/c7cd2aba486e8ff53495153d611b852e860455d8)