3√2(cos35-sin35)/cos100

исправил опечатку

во 2 строке была

3√2(cos35-sin35)/cos100==3√2(sin(45-10)-sin(45+10))/cos(90+10)==3√2(sin(45)*cos(10)-sin(10)*cos(45)-sin(45)*cos(10)-sin(10)*cos(45))/sin(10)==3√2(-2*sin(10)*cos(45))/sin(10)==3√2(-2*cos(45))=3√2(-2*√2/2)=-6

3√2(cos35-cos55)/cos(90+10)=3√2*2sin45sin10/(-sin10)=-3√2*2*√2/2=-6