# Recent questions tagged trigonometry

1
If $\ Sinx+Sin^{2} x=1$ then $\ Cos^{8}x+ 2 \ Cos^{6} x+ \ Cos^{4} x$ equals to : $0$ $-1$ $1$ $2$
1 vote
2
$\ Sin^{-1}\left [ \frac{3}{5} \right ] + \tan^{-1}\left [ \frac{1}{7} \right ]=$ $\frac{\pi }{4}$ $\frac{\pi }{2}$ $\ Cos^ {-1} \frac{4}{5}$ $\pi$
1 vote
3
If $\theta$ is an acute angle and $\tan\theta+\cot\theta =2$, Find the value of $\tan ^{7}\theta +\cot ^{7}\theta$. $-2$ $1$ $2$ $0$
The expressions $\dfrac{\tan A}{1-\cot A}+\dfrac{\cot A}{1-\tan A}$ can be written as: $\sin A \ \cos A+1$ $\sec A \ cosec A+1$ $\tan A+ \cot A+1$ $\sec A +cosec A$
If $x=\cos1^{\circ} \cdot \cos2^{\circ} \cdot \cos3^{\circ}\dots\cos89^{\circ}$ and $y=\cos2^{\circ}\cos6^{\circ}\cos10^{\circ}\dots\cos86^{\circ}$ then what the integer is nearest to $\dfrac{2}{7}\log _{2} \left( \dfrac{y}{x}\right )$is: $19$ $17$ $15$ $21$
If $cosec\theta-\sin\theta=1$ and $\sec\theta-\cos\theta=m$, then $l^{2}m^{2}(l^{2}+m^{2}+3)$ equals to: $1$ $2$ $2 \sin\theta$ $\sin\theta \cos\theta$