sin105 = sin(90+15) = sin90cos15 + cos90sin15 = cos15cos15 = cos(90-75) = cos90cos75 + sin90sin75 = -sin75tg75 = sin75 / cos75
cos15 (-sin75) / cos75 = (-sin75sin15) / cos75 = -sin(75+15) = -sin90 = -1
Ответ: -1
sin105 = sin(90+15) = sin90cos15 + cos90sin15 = cos15
cos15 = cos(90-75) = cos90cos75 + sin90sin75 = -sin75
tg75 = sin75 / cos75
cos15 (-sin75) / cos75 = (-sin75sin15) / cos75 = -sin(75+15) = -sin90 = -1
Ответ: -1