If $$A = (\cos 12^\circ - \cos 36^\circ )(\sin 96^\circ + \sin 24^\circ )$$ and $$B = (\sin 60^\circ - \sin 12^\circ )(\cos 48^\circ - \cos 72^\circ )$$, then what is $${A \over B}$$ equal to?

The value of $$\tan 9^\circ - \tan 27^\circ - \tan 63^\circ + \tan 81^\circ $$ is equal to

The value of $$\sqrt 3 \cos ec20^\circ - \sec 20^\circ $$ is equal to

Angle $$\alpha$$ is divided into two parts A and B such that A $$-$$ B = x and tan A : tan B = p : q. The value of sin x is equal to