Solution
Find the Sine, cosine, tangent of - 120
[tex]\sin (-120)[/tex][tex]\begin{gathered} \mathrm{Use\: the\: following\: property\colon}\: \sin \mleft(-x\mright)=-\sin \mleft(x\mright) \\ \sin \mleft(-120^{\circ\: }\mright)=-\sin \mleft(120^{\circ\: }\mright) \\ =-\sin \mleft(120^{\circ\: }\mright) \\ =-\frac{\sqrt{3}}{2} \end{gathered}[/tex][tex]\cos (-120)[/tex]