Explicație pas cu pas:
4)
[tex]\sin(180) = 0 \\ \cos(180) = - 1 \\ \tg(180) = \frac{\sin(180)}{\sin(180)} = 0\\ \ctg(180) \: nedefinit [/tex]
[tex]\sin(300) = \sin(360 - 60) = \sin(- 60) = - \sin(60) \\ = > \sin(300) = - \frac{ \sqrt{3} }{2}[/tex]
[tex]\cos(300) = \cos(360 - 60) = \cos( - 60) = \cos(60) \\ = > \cos(300) = \frac{1}{2} \\[/tex]
[tex]\tg(300) = \frac{\sin(300)}{\sin(300)} = \frac{ - \frac{ \sqrt{3} }{2} }{ \frac{1}{2} } = - \sqrt{3} \\ [/tex]
[tex]\ctg(300) = \frac{1}{\tg(300)} = \frac{1}{ - \sqrt{3} } = - \frac{ \sqrt{3} }{3} \\ [/tex]
