Вычислите:3sin159°*cos69°+3sin111°*cos339°+2tg201°*tg249°

Question

Вычислите:3sin159°*cos69°+3sin111°*cos339°+2tg201°*tg249°

Answer 1

3sin(180-21)cos(90-21)+3sin(90+21)cos(360-21)+2tg(180+21)tg(270-21)=
3sin21sin21+3cos21cos21+2tg21ctg21=3(sin²21+cos²21)+2=3+2=5