SIN^6α+COS^6α=(sin^2a+cos^2a)(sin^4a-sin^2acos^2a+cos^4a)=sin^4a-sin^2acos^2a+cos^4a=(sin^2a+cos^2a)^2-3sin^2acos^2a=1-3/4*(sin2a)^2 COS2α=-1/3 (COS2α)^2=1/9(sin2a)^2=8/9=1-3/4*8/9=11/...