Преобразуй в произведение. $\cos\dfrac{\pi}{4}+\cos\dfrac{\pi}{7}$ $2\cos\dfrac{11\pi}{56}\cos\dfrac{3\pi}{56}$ $2\cos\dfrac{11\pi}{28}\cos\dfrac{3\pi}{28}$ $2\cos\dfrac{11\pi}{28}\sin\dfrac{3\pi}{28}$ $2\sin\dfrac{11\pi}{56}\sin\dfrac{3\pi}{56}$

Задание

Преобразуй в произведение.

\(\cos\dfrac{\pi}{4}+\cos\dfrac{\pi}{7}\)

Выбери верный вариант.

\(2\cos\dfrac{11\pi}{56}\cos\dfrac{3\pi}{56}\)
\(2\cos\dfrac{11\pi}{28}\cos\dfrac{3\pi}{28}\)
\(2\cos\dfrac{11\pi}{28}\sin\dfrac{3\pi}{28}\)
\(2\sin\dfrac{11\pi}{56}\sin\dfrac{3\pi}{56}\)