Sin(47pi/6) tg(25pi/4) ctg(27pi/4) cos(21pi/4)
Sin(47π/6)=sin(6π+11π/6)=-sinπ/6=-1/2 tg(25π/4)=tg(6π+π/4)=1 ctg(27π/4)=ctg(6π+3π/4)=-1 cos(21π/4)=cos(4π+5π/4)=-√2/2
Спасибо.