Solution.
=tg(45π+α)(2cos2(4π+α))1−2sin2α−tgα+sin(2π+α)−cos(2π−α)=
=[1−2sin2x=cos2x,tg2x=1+cosxsinx,x=π+2πn,n∈Zcos22x=21+cosx]==1+cos(25π+2α)sin(25π+2α)⋅(1+cos(2π+2α))cos2α−tgα+cosα−sinα==1−sin2αcos2α⋅(1−sin2α)cos2α−cosαsinα+cosα−sinα==(1−cosαsinα)+(cosα−sinα)=cosαcosα−sinα+(cosα−sinα)==(cosα−sinα)(cosα1+1)=cosα(cosα−sinα)(1+cosα)==cosα22(22cosα−22sinα)(1+cos22α−sin22α)==cosα2(cos4πcosα−sin4πsinα)⋅2cos22α==cosα22(cos4πcosα−sin4πsinα)cos22α==[cosxcosy−sinxsiny=cos(x+y)]=cosα22cos(4π+α)cos22α
Answer: cosα22cos(4π+α)cos22α.