Rozwiązania:
Zadanie 1.
[tex]sin\frac{7}{6}\pi =sin(\pi +\frac{\pi }{6}) =sin\frac{\pi }{6}=\frac{1}{2} \\cos\frac{4}{3}\pi=cos(\pi+\frac{\pi}{3}) =-cos\frac{\pi}{3}=-\frac{1}{2} \\cos(135)=cos(180-45)=-cos(45)=-\frac{\sqrt{2} }{2}\\ sin(1200)=sin(3*360+120)=sin(120)=sin(180-60)=sin60=\frac{\sqrt{3} }{2}[/tex]
Zadanie 2.
[tex]sin(10)+cos(100)=sin(10)+cos(90+10)=sin(10)-sin(10)=0[/tex]
Zadanie 3.
[tex]sin(12)*cos(18)+cos(12)*sin(18)=sin(12+18)=sin(30)=\frac{1}{2}[/tex]
[tex]cos(105)=cos(60+45)=cos(60)*cos(45)-sin(60)*sin(45)=\frac{1}{2} *\frac{\sqrt{2} }{2}-\frac{\sqrt{3} }{2} *\frac{\sqrt{2} }{2} =\frac{\sqrt{2}-\sqrt{6} }{4}[/tex]
