Найдите значение выражения log2 sin(n/12)+log2 sin(n/6)+log2 sin(5n/12)

Sin5π/12=cosπ/12
log2_sinπ/12+log2_cosπ/12=log2_(sinπ/12·cosπ/12)=log2_(1/2sinπ/6)=log2_1/4=-2
log2_(sinπ/6)log2_(1/2)=-1
-1-2=-3