Question

упростите
cos(п/3+b)*cos(п/3-b), cosb=2
помогитеее

Answer 1

Ответ:cos(π/3+b)•cos(π/3-b)=cosπ/3•cosb-sinπ/3•sinb+cosπ/3•cosb+sinπ/3•sinb=2cosπ/3•cosb=cosb