If the function f : R $$ \to $$ R is defined by f(x) = (x² + 1)³⁵, $$\forall $$ x$$ \in $$R, then f is

The value of $$\cos 15^\circ \cos 7{{1^\circ } \over 2}\sin 7{{1^\circ } \over 2}$$ is

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

The points ($$-$$a, $$-$$b), (a, b), (0, 0) and (a², ab), a $$ \ne $$ 0, b $$ \ne $$ 0 are always