Question

Cos11пи/12-cos5пи/2 с подробным решением пожалуйста!!!!

Answer 1

-2sin[(11π/12-5π/2)/2]sin[(11π/12+5π/2)/2]=-2sin(-19π/24)sin(41π/24)=
=2sin(π-5π/24)sin(2π-7π/24)=2*(-sin5π/24)*(-sin7π/24)=2sin5π/24*sin7π/24