The equation $\sqrt 3 \sin x + \cos x = 4$ has
Only one solution
Two solutions
Infinitely many solutions
No solution
The general solution of $\sin x - 3\sin 2x + \sin 3x = $ $\cos x - 3\cos 2x + \cos 3x$ is
The number of solutions of $|\cos x|=\sin x$, such that $-4 \pi \leq x \leq 4 \pi$ is.
The total number of solution of $sin^4x + cos^4x = sinx\, cosx$ in $[0, 2\pi ]$ is equal to
If ${\sec ^2}\theta = \frac{4}{3}$, then the general value of $\theta $ is
If $\cos \theta = - \frac{1}{{\sqrt 2 }}$ and $\tan \theta = 1$, then the general value of $\theta $ is