The region represented by| x – y | $$ \le $$ 2 and | x + y| $$ \le $$ 2 is bounded by a :

If the two lines x + (a – 1) y = 1 and 2x + a²y = 1 (a$$ \in $$R – {0, 1}) are perpendicular, then the distance of their point of intersection from the origin is :

Slope of a line passing through P(2, 3) and intersecting the line, x + y = 7 at a distance of 4 units from P, is :

Suppose that the points (h,k), (1,2) and (–3,4) lie on the line L₁ . If a line L₂ passing through the points (h,k) and (4,3) is perpendicular to L₁ , then $$k \over h$$ equals :