71
$\cos \frac{2 \pi}{15} \cos \frac{4 \pi}{15} \cos \frac{8 \pi}{15} \cos \frac{16 \pi}{15}=\frac{1}{16}$
A
TRUE
B
FALSE
72
One value of $\theta$ which satisfies the equation $\sin^4\theta-2\sin^2\theta-1$ lies between $\theta$ and $2\pi$.
A
TRUE
B
FALSE
73
If $\operatorname{cosec} x=1+\cot x$, then $x=2 n \pi, 2 n \pi+\frac{\pi}{2}$
A
TRUE
B
FALSE
74
If $\tan \theta+\tan 2 \theta+\sqrt{3} \tan \theta \tan 2 \theta=\sqrt{3}$, then $\theta=\frac{n \pi}{3}+\frac{\pi}{9}$.
A
TRUE
B
FALSE
75
If $\tan (\pi \cos \theta)=\cot (\pi \sin \theta)$, then $\cos \left(\theta-\frac{\pi}{4}\right)= \pm \frac{1}{2 \sqrt{2}}$.
A
TRUE
B
FALSE