Question

обчисліть cos²30°-2 sin²30°
3 cos²45°-2 cos²60°
4 sin30°- √3 cos30°

Answer 1

cos^2(30)-2sin^2(30)=3/4-1/20=1,4;
3 cos²45°-2 cos²60°=3/2-1/2=1;
4 sin30°- √3 cos30°=2-1.5=0.5;