If $\mathrm{f}(x)=\sqrt{1+\cos ^2\left(x^2\right)}$, then $\mathrm{f}^{\prime}\left(\frac{\sqrt{\pi}}{2}\right)$ is

The modulus of the square root of the complex number $6+8 \mathrm{i}$ (where $\mathrm{i}=\sqrt{-1}$ ) is

If $[x]^2-5[x]+6=0$, where [.] denotes the greatest integer function, then

The area of smaller part between the circle $x^2+y^2=4$ and the line $x=1$ is _________ sq.units.