Question

Вычислить: а) sin 13П/6 б) tg (-11П/6) в) cos П+ctg 4П/3 г) sin 2П/3 д) cos 150 е) tg 300 дальше во вложении

Answer 1

а) sin 13π/6= sin (2π+π/6)=sinπ/6=0.5;

б) tg (-11π/6)=-tg (11π/6)=-tg (2π-π/6)=tg (π/6)=√3/3

в) cos π+ctg 4π/3=-1+ctg(π+ π/3)=-1+ctgπ/3=-1+√3

г) sin 2π/3= sin(π-π/3)=sin π/3=√3/2

д) cos 150°=- cos30°=-√3/2

е) tg 300°= tg(360°-60°)=-tg60°=-√3

г) sin 5π/6= sin(π-π/6)=sin π/6=1/2

е) sin(- 5π/6)= -sin(π-π/6)=-sin π/6=-1/2

ж)  sin(47π/6)= sin(2π*4-π/6)=-sin π/6=-1/2

з) √3*cos2π/3*cosπ/6=√3*(-1/2)*(√3/2)=-3/4=-0.75

и)е) cos5π/4=cos(π+π/4)=-cosπ/4=-√2/2