Пожалуйста, помогите решить. ctg п/6 sin2a — tg п/3 cos^2 2aпри a=п/24

cosa=±Ö1-sin2a=(1-tg2a/2) / (1+tg2a/2) sina=±Ö1/1+ctg2a=(2tga/2) / (1+tg2a/2) cos (ab)=sinasinbcosacosb sin (a±b)=sinacosb±sinbcosa tg (a+b)=sin (a+b) /cos (a+b)=(tga+tgb) / (1-tgatgb) tg (a-b)=(tga-tgb) / (1+tgatgb) ctg (a+b)=(ctgactgb-1) / (ctga+ctgb) ctg (a-b)=(ctgactgb+1) / (ctgb-ctga) sin2a=2sinacosa=(2tga) / (1+tg2a) cos2a=cos2a-sin2a=(1-tg2a) / (1+tg2a)=2cos2a-1=1-2sin2a tg2a=2tga/ (1-tg2a) ctg2a=(ctg2a-1) /2ctga ctg2a=(ctg2a-1) /2ctga cos2a/2=1+cosa/2 cos2a=(1+cos2a) /2 sin2a/2=1-cosa/2 sin2a=(1-cos2a) /2 cosa/2=±Ö1+cosa/2 sina/2=±Ö1-cosa/2 tga/2=±Ö1-cosa/1+cosa=(sina) / (1+cosa)=(1-cosa) /sina ctga/2=±Ö1+cosa/1-cosa=sina/ (1-cosa)=(1+cosa) /sina sina+cosa=Ö2 cos (P/4-a) sina-cosa=Ö2 sin (a-P/4) cosa-sina=Ö2 sin (P/4-a) cosa+cosb=2cos (a+b) /2cos (a-b) /2 cosa-cosb=-2sin (a+b) /2sin (a-b) /2 sina+sinb=2sin (a+b) /2cos (a-b) /2 sina-sinb=2sin (a-b) /2cos (a+b) /2 tga±tgb=(sin (a±b) /cosacosb cosacosb=1/2 (cos (a-b)+cos (a+b) sinasinb=1/2 (cos (a-b) -cos (a+b) sinacosb=1/2 (sin (a+b)+sin (a-b) tga=(2tga/2) / (1-tg2a/2) cosa=±Ö1-sin2a=(1-tg2a/2) / (1+tg2a/2) sina=±Ö1/1+ctg2a=(2tga/2) / (1+tg2a/2) cos (ab)=sinasinbcosacosb sin (a±b)=sinacosb±sinbcosa tg (a+b)=sin (a+b) /cos (a+b)=(tga+tgb) / (1-tgatgb) tg (a-b)=(tga-tgb) / (1+tgatgb) ctg (a+b)=(ctgactgb-1) / (ctga+ctgb) ctg (a-b)=(ctgactgb+1) / (ctgb-ctga) sin2a=2sinacosa=(2tga) / (1+tg2a) cos2a=cos2a-sin2a=(1-tg2a) / (1+tg2a)=2cos2a-1=1-2sin2a tg2a=2tga/ (1-tg2a) ctg2a=(ctg2a-1) /2ctga ctg2a=(ctg2a-1) /2ctga cos2a/2=1+cosa/2 cos2a=(1+cos2a) /2 sin2a/2=1-cosa/2 sin2a=(1-cos2a) /2 cosa/2=±Ö1+cosa/2 sina/2=±Ö1-cosa/2 tga/2=±Ö1-cosa/1+cosa=(sina) / (1+cosa)=(1-cosa) /sina ctga/2=±Ö1+cosa/1-cosa=sina/ (1-cosa)=(1+cosa) /sina sina+cosa=Ö2 cos (P/4-a) sina-cosa=Ö2 sin (a-P/4) cosa-sina=Ö2 sin (P/4-a) cosa+cosb=2cos (a+b) /2cos (a-b) /2 cosa-cosb=-2sin (a+b) /2sin (a-b) /2 sina+sinb=2sin (a+b) /2cos (a-b) /2 sina-sinb=2sin (a-b) /2cos (a+b) /2 tga±tgb=(sin (a±b) /cosacosb cosacosb=1/2 (cos (a-b)+cos (a+b) sinasinb=1/2 (cos (a-b) -cos (a+b) sinacosb=1/2 (sin (a+b)+sin (a-b) tga=(2tga/2) / (1-tg2a/2)