Prove that $=\frac{\sin 5 x-2 \sin 3 x+\sin x}{\cos 5 x-\cos x}=\tan x$
We have
${\text{L}}{\text{.H}}{\text{.S}}{\text{.}}\frac{{\sin 5x - 2\sin 3x + \sin x}}{{\cos 5x - \cos x}}$
$ = \frac{{\sin 5x + \sin x - 2\sin 3x}}{{\cos 5x - \cos x}}$
$ = \frac{{2\sin 3x\cos 2x - 2\sin 3x}}{{ - 2\sin 3x\sin 2x}}$
$ = - \frac{{\sin 3x(\cos 2x - 1)}}{{\sin 3x\sin 2x}}$
$ = \frac{{1 - \cos 2x}}{{\sin 2x}}$
$ = \frac{{2{{\sin }^2}x}}{{2\sin x\cos x}}$
$ = \tan \,x = R.H.S$
For $A = 133^\circ ,\;2\cos \frac{A}{2}$ is equal to
$\sin 4\theta $ can be written as
$\cos \frac{\pi }{7}\cos \frac{{2\pi }}{7}\cos \frac{{3\pi }}{7} =$
Prove that $\frac{\sin x-\sin 3 x}{\sin ^{2} x-\cos ^{2} x}=2 \sin x$
The value of $\left( {1 + \cos \frac{\pi }{9}} \right)\left( {1 + \cos \frac{{3\pi }}{9}} \right)\left( {1 + \cos \frac{{5\pi }}{9}} \right)\left( {1 + \cos \frac{{7\pi }}{9}} \right)$ is