sin(47pi/6)
tg(25pi/4)
ctg(27pi/4)
cos(21pi/4)

Спасибо.

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