Найдите значение выражения 14/sin (-27п/4) cos(29п/4)
Решение 14/sin (-27π/4) cos(29π/4) = - 14 / [sin(28π/4 - π/4) * cos(28π/2 + π/4)] = = - 14 / [sin(7π - π/4) * cos(7π + π/4)] = - 14 / [(sinπ/4) * (- cosπ/4)] = = 14 / (√2/2 * √2/2) = 14*4 / 2 = 28