а) 2\sin \dfrac{\pi}{8} \cos \dfrac{\pi}{8} = ; б) \left( \cos \dfrac{\pi}{12} -\sin \dfrac{\pi}{12}\right) \left( \cos \dfrac{\pi}{12} + \sin \dfrac{\pi}{12}\right)= .

Задание

Вычисли

а) \(2\sin \dfrac{\pi}{8} \cos \dfrac{\pi}{8} = \) [ ];

б) \(\left( \cos \dfrac{\pi}{12} -\sin \dfrac{\pi}{12}\right) \left( \cos \dfrac{\pi}{12} + \sin \dfrac{\pi}{12}\right)= \) [ ].