Question

вычислите cos(a+п/6) - cos(a-п/6)
a- альфа

Answer 1

$cos(alpha+fracpi6)-cos(alpha-fracpi6)=\=(cosalphacosfracpi6-sinalphasinfracpi6)-(cosalphacosfracpi6+sinalphasinfracpi6)=\=cosalphacosfracpi6-sinalphasinfracpi6-cosalphacosfracpi6-sinalphasinfracpi6=\=2sinalphasinfracpi6=-2cdotfrac12sinalpha=-sinalpha$