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.

If the function $f(x)=\left\{\begin{array}{cl}\frac{\cos a x-\cos b x}{\cos c x-\cos b x} & , \text { if } x \neq 0 \\ -1 & , \text { if } x=0\end{array}\right.$ is continuous at $x=0$, then $\mathrm{a}^2, \mathrm{~b}^2, \mathrm{c}^2$ are in

$$ \int_0^1 \tan ^{-1} x d x= $$