Помогите,пожалуйста.Даю 50 баллов. =)
1.Вычислите:
tg(-5π/6);
sinπ-tg3π/4;
tgπ*ctgπ/4+cosπ/2*sin(-2π/3);
sin150°-cos720°+tg225°.

1) tg(-5π/6) = -tg5π/6 = = 1/√32) Sinπ - tg3π/4 = 0 + 1 = 13) tgπ·Ctg π/4 + Cosπ/2·Sin(-2π/3) = 0·1 - 1·√3/2 = -√3/24) Sin150° - Cos720° + tg225° = = Sin(180°-30°) - 1 + tg(180 °+45°) = Sin30° -1 +1 = 1/2