)решить: 1)-38sin13/sin 347 2)37cos171/cos9 3)-20tg89/tg91 - вопрос №3131421138133472371719320899141116722 от CleverBoy17 26.07.2021 20:40

Question

Алгебра: )решить: 1)-38sin13/sin 347 2)37cos171/cos9 3)-20tg89/tg91 4)11tg167*tg225 5)28sin68/sin292 6)28cos68/cos 112 7)4tg108/tg72 8)11sin421/sin61

CleverBoy17 · Answer

1)-38sin13/sin 347=-3sin13/sin(360-13)=-3sin13/(-sin13)=3
2)37cos171/cos9=37cos(180-9)/cos9=-37cos9/cos9=-37
3)-20tg89/tg91=-20tg(90-1)/tg(90+1) =-20ctg1/(-ctg1)=20
4)11tg167*tg225=11tg(180-13)*tg(180+45)=-11tg13*tg45=-11tg13*1=-13tg13
5)28sin68/sin292=28sin(90-22)/sin(270+22)=28cos22/(-cos22)=-28
6)28cos68/cos 112=28cos(90-22)/cos(90+22)=28sin22/(-sin22)=-28
7)4tg108/tg72=4tg(90+18)/tg(90-18)=-4ctg18/ctg18=-4
8)11sin421/sin61=11sin(360+61)/sin61=11sin61/sin61=11