Cos(−25 × π / 3) + sin(−π / 12) × cos(−π / 12) помогие решить.

Question

Cos(−25 × π / 3) + sin(−π / 12) × cos(−π / 12) помогие решить.

Answer 1

Cos(-8π-π/3)+1/2(sin(-π/12+π/12)+sin(-π/12-π/12))=cosπ/3+1/2(sin0-sinπ/6)=
=1/2+1/2*(-1/2)=1/2-1/4=1/4