J P Mohindru and Bharat Mohindru Solutions for Chapter: Introduction to Trigonometry, Exercise 8: COMPETITION FILE

If $\cos 9\alpha =\sin \alpha$ and $9\alpha <90°,$ then the value of $\tan 5\alpha$ is:

If $△ABC$ is right-angled at $C$, then the value of $\cos (A+B)$ is

If $\sin A+{\sin }^{2}A=1$, then the value of the expression $({\cos }^{2}A+{\cos }^{4}A)$ is:

Given that $\sin \alpha =\frac{1}{2}$ and $\cos \beta =\frac{1}{2}$, then the value of $(\alpha +\beta )$ is

The value of the expression: $\left[\frac{{\sin }^{2}22°+{\sin }^{2}68°}{{\cos }^{2}22°+{\cos }^{2}68°}+{\sin }^{2}63°+\cos 63°\sin 27°\right]$ is:

If $4\tan \theta =3$, then $\left(\frac{4\sin \theta -\cos \theta }{4\sin \theta +\cos \theta }\right)$ is equal to

If $\sin \theta -\cos \theta =0$, then the value of $({\sin }^4\theta +{\cos }^4\theta )$ is

$\sin (45°+\theta )-\cos (45°-\theta )$ is equal to: