MCQ
$\cos \frac{\pi }{7}\cos \frac{{2\pi }}{7}\cos \frac{{3\pi }}{7} =$
- A$-\frac{1}{8}$
- B$\frac{1}{16}$
- ✓$\frac{1}{8}$
- DNone
$\frac{1}{2 \times 2 \sin \frac{\pi}{7}}\left[2 \sin \frac{2 \pi}{7} \cos \frac{2 \pi}{7} \cos \frac{3 \pi}{7}\right]$
$\frac{1}{2.4\sin \left(\frac{\pi}{3}\right)}\left(2 \sin 4 \frac{\pi}{7} \cos \frac{3 \pi}{7}\right)$
$\frac{1}{8 \sin \left(\frac{\pi}{7}\right)}\left[\sin (\pi)+\sin \left(\frac{\pi}{7}\right)\right]$
$\frac{\sin (\pi / 7)}{8 \sin (\pi / 7)}=\frac{1}{8}$
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.