Calculati sinusul, cosinusul, tangenta : 1) 120. 2) 135. 3) 150.

Sin120°=sin (90°+30°) = cos30°=√3/2

или sin120°=sin (180°-60°) = sin60°=√3/2

cos120°=cos (90°+30°) = - sin30°=-1/2

tg120°=tg (90°+30°) = - ctg30°=-√3

2. sin135°=sin (90°+45°) = sin45°=√2/2

cos135°=cos (90°+45°) = - sin45°=-√2/2

tg135°=tg (90°+45°) = - ctg45°=-1

ctg135°=ctg (90°+45°) = - tg45°=-1

3. sin150°=sin (90°+60°) = sin60°=√3/2

cos150°=sin (180°-30°) = sin30°=1/2

tg150°=tg (90°+60°) = - ctg60°=-1/√3