Question

   упростите
    cos5$pi$/6 * cos$pi$/3 +sin5 $pi$ /6sin$pi$ /3
    ------------------------------------------------------------
    tg(3$pi$ /4- $alpha$)

Answer 1

(cos5π/6cosπ/3+sin5π/6sinπ/3)/tg(3π/4-a)=cos(5π/6-π/3)/tg(3π/4-a)
=cosπ/2:tg(3π/4-a)=0:tg(3π/4-a)=0