The area, enclosed by the curves $$y = \sin x + \cos x$$ and $$y = \left| {\cos x - \sin x} \right|$$ and the lines $$x = 0,x = {\pi \over 2}$$, is :

The distance of line $$3y - 2z - 1 = 0 = 3x - z + 4$$ from the point (2, $$-$$1, 6) is :

The numbers of pairs (a, b) of real numbers, such that whenever $$\alpha$$ is a root of the equation x² + ax + b = 0, $$\alpha$$² $$-$$ 2 is also a root of this equation, is :

Let P₁, P₂, ......, P₁₅ be 15 points on a circle. The number of distinct triangles formed by points P_i, P_j, P_k such that i +j + k $$\ne$$ 15, is :