Вычислить : 1) (11cos287-25sin557)/sin170=2)(2cos11π/5+8sin13π/10)/cosπ/5= - вопрос №30502421112872555717022115813105 от Kalltan 13.10.2021 19:28

Question

Алгебра: Вычислить : 1) (11cos287-25sin557)/sin170=2)(2cos11π/5+8sin13π/10)/cosπ/5= 3)(cos105*cos5+sin105*cos85)/(sin195*cos5+cos195*sin185)

Kalltan · Answer

1)(-11sin17+25sin17)/sin10=14sin17/sin10
2)(2cosπ/5+8sin3π/10)/cosπ/5=(2cosπ/5+8cosπ/5)/cosπ/5=10cosπ/5 / cosπ/5=10
3)(cos105cos5+sin105sin5)/(sin195cos5-cos195sin5)=cos(105-5)/sin(195-5)=
=cos100/sin190=-sin10/-sin10=1