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

$$\sqrt {1 + \sin A} = - \left( {\sin {A \over 2} + \cos {A \over 2}} \right)$$ is true, if

In triangle ABC, if $${{{{\sin }^2}A + {{\sin }^2}B + {{\sin }^2}C} \over {{{\cos }^2}A + {{\cos }^2}B + {{\cos }^2}C}} = 2$$, then the triangle is