Question

найдите значение выражения (Cos π/12+cos π/6)/ cos π/8•cosπ/24

Answer 1

$frac{cosfrac{pi}{12}+cosfrac{pi}{6}}{cosfrac{pi}{8}cdot cosfrac{pi}{24}} = frac{2cosfrac{frac{pi}{12}+frac{pi}{6}}{2}cdot cos frac{frac{pi}{6}-frac{pi}{12}}{2} }{cosfrac{pi}{8}cdot cosfrac{pi}{24}} = frac{2cosfrac{3pi}{24}cdot cosfrac{pi}{24}}{cosfrac{pi}{8}cdot cosfrac{pi}{24}} = frac{2cosfrac{pi}{8}}{cosfrac{pi}{8}} =2$