List of top Mathematics Questions on Trigonometric Functions asked in UPSEE

The value of $\sin 20^{\circ} \; \sin 40^{\circ} \; \sin 80^{\circ} $ equals
The value of $\sin^{4} \frac{\pi}{8} + \sin^{4} \frac{3 \pi}{8} + \sin^{4} \frac{5\pi}{8} + \sin^{4} \frac{7\pi}{8} $ is
If $\cos \, 3x \, \cos \, 2x \, \cos \, x = \frac{1}{4} $ and $0 < x < \frac{\pi}{4}$, then the value of $x$ is