[tex]2sin 150^o-4cos120^o = 2sin(180^o - 30^o) - 4cos(180^o-60^o) = \\ = 2sin30^o - 4(-cos60^o) = \not{2}^1 \cdot \frac{1}{\not{2}_1} - \not{4}^2 \cdot (-\frac{1}{\not{2}_1}) = 1 +2=3[/tex]
[tex]2\sin 150^o-4\cos120^o=\\\\=2\sin( 90^o+60^o)-4\cos(90^o+30^o)=\\\\=2\cos 60^o-4(-\sin30^o)=\\\\=2\cdot\frac12-4\cdot(-\frac12)=\\\\=1+2\,=\,3[/tex]
