cos 5П/12 - cos П/12 + sin(arccos 1/2)=2sinП/4sin(-П/3)+sin(+-П/3)= 1)=-2*sqrt(2)/2*sqrt(3)/2+sqrt(3)/2=sqrt(3)/2(1-sqrt(2)) 2)=-2*sqrt(2)/2*sqrt(3)/2-sqrt(3)/2=-sqrt(3)/2(1+sqrt(2))