The polar form of the complex number $z = \dfrac{1}{1 + i}$, (where $i = \sqrt{-1}$) is

The number of cubic equations that can be formed with the coefficients 0, 3, 2, 4, 5, 6 when repetition of coefficients is allowed, is....

$\tan 105^\circ = $ ......

The number of solutions in $\left[0, \dfrac{\pi}{2}\right)$ of the equation $\cos 3x \cdot \tan 5x = \sin 7x$ is