Question

вычислите
1) sin(-n/6)cos(-n/4)- sin(-n/4)cos(-n/6)
2)sin(-n/4)ctg(-n/4)-cos(-n/6)tg(-n/4)
3)sin (-n)+cos(-n/2)tg(-n/4)+ctg(-n/2)

Answer 1

1) sin(-n/6)cos(-n/4)- sin(-n/4)cos(-n/6)=-1/2*√2/2+√2/2*√3/2=√6/4-√2/4=√2/4(√3-1);
2)sin(-n/4)ctg(-n/4)-cos(-n/6)tg(-n/4)=√2/2*1+√3/2*1=√2/2+√3/2=1/2(√2+3);
3)sin (-n)+cos(-n/2)tg(-n/4)+ctg(-n/2)=0-0*1-0=0.