If the conductivity of mercury at 0$$^\circ$$C is 1.07 $$\times$$ 10⁶ S m^$$-$$1 and the resistance of a cell containing mercury is 0.243$$\Omega$$, then the cell constant of the cell is x $$\times$$ 10⁴ m^$$-$$1. The value of x is ____________. (Nearest integer)

A peptide synthesized by the reactions of one molecule each of Glycine, Leucine, Aspartic acid and Histidine will have _________ peptide linkages.

Let f : R $$\to$$ R be a continuous function. Then $$\mathop {\lim }\limits_{x \to {\pi \over 4}} {{{\pi \over 4}\int\limits_2^{{{\sec }^2}x} {f(x)\,dx} } \over {{x^2} - {{{\pi ^2}} \over {16}}}}$$ is equal to :

$${\cos ^{ - 1}}(\cos ( - 5)) + {\sin ^{ - 1}}(\sin (6)) - {\tan ^{ - 1}}(\tan (12))$$ is equal to :

(The inverse trigonometric functions take the principal values)