$$\int \tan ^{-1}\left(\frac{1-\sin x}{1+\sin x}\right) d x=$$

The mean and variance of seven observations are 8 and 16 respectively. If 5 of the observations are $2,4,10,12,14$, then the square root of product of remaining two observations is

The equation of the tangent to the curve $y=1-\mathrm{e}^{\frac{x}{3}}$ at the point of intersection with Y -axis is

$$\int \frac{\left(x^2+1\right)}{(x+1)^2} \mathrm{~d} x=$$