4sin210-3√2cos(-135)

Question

4sin210-3√2cos(-135)

Answer 1

4sin210°-3√2cos(-135°)=4sin(180°+30°)+3√2cos(90°+45°)=
= -4sin30°-3√2cos45°=-4.0,5-3√2.√2/2=-2-3=-5
Otvet: -5

( cos(-x)=cosx, sin(-x)=-sinx, sin30°=0,5, cos45°=(√2)/2 )