A polygon of nine sides, each of length $$2$$, is inscribed in a circle. The radius of the circle is .................

In a triangle, the lengths of the two larger sides are $$10$$ and $$9$$, respectively. If the angles are in $$AP$$. Then the length of the third side can be

The set of all $$x$$ for which $$in\left( {1 + x} \right) \le x$$ is equal to ..........

The smallest positive root of the equation, $$\tan x - x = 0$$ lies in