$\cos 15^\circ = $
Find the value of $\sin 15^{\circ}$
If $(1 + \sin A)(1 + \sin B)(1 + \sin C)$$ = (1 - \sin A)(1 - \sin B)(1 - \sin C),$ then each side is equal to
Find the value of the trigonometric function $\cot \left(-\frac{15 \pi}{4}\right)$
Find the values of other five trigonometric functions if $\cot x=\frac{3}{4}, x$ lies in third quadrant.