Помогите упростить: 1) sin85tg5 2) 1 - sin18cos72 please!!!

Question

Помогите упростить: 1) sin85tg5 2) 1 - sin18cos72 please!!!

Answer 1

1) sin85•tg5= sin(90-5)tg5=cos5(sin5/cos5) = sin5 2) 1 - sin18cos72 = 1 - sin(90-72)cos72 = 1-cos72cos72 = 1-(cos72)^2 = (sin72)^2