[tex]\displaystyle\bf\\Calculam~sin~150~asa~cum~ai~mentionat~in~comentariu.\\\\Unghiul~de~150~este~in~cadranul~2.\\\\\^Il~aducem~la~cadranul~1.\\\\sin(150)=sin(180-30)=sin(30)=\boxed{\bf\frac{1}{2}}[/tex]
Sinusul unui unghi este egal cu sinusul complementului său.
[tex]\it sin150^o=sin(180^o-150^o)=sin30^o=\dfrac{1}{2}[/tex]
