1)0,5*2cos6xcosx-1/2(1+cos4x)+1/2(1-cos6x)=cos6xcosx-1/2-1/2cos4x-1/2cos6x==cos6xcosx-1/2(cos6x+cos4x)=cos6xcosx-1/2*2cos5xcosx=cos6xcosx-cos5xcosx==cosx(cos6x-cos5x)=cosx*(-2sin5,5xsin0,5x)=0cosx=0⇒x=π/2+πnsin5,5x=0⇒5,5x=πn⇒x=2πn/11sin0,5x=0⇒0,5x=πn⇒2πn2)2cos4x-2sinxcos3x-2sin3xcosx=02cos4x-2(sinxcos3x+sin3xcosx)=02cos4x-2sin4x=02cos²2x-2sin²2x-4sin2xcos2x=0 /-2cos²2x≠0tg²2x+2tgx-1=0tgx=aa²+2a-1=0D=4+4=8a1=(-2-2√2)/2=-1-√2⇒tgx=-(1+√2)⇒x=-arctg(1+√2)+πna2=-1+√2⇒tgx=√2-1⇒x=arctg(√2-1)+πn