Question
If the sum of the distances of a point from two perpendicular lines in a plane is 1, then its locus is-
A.
square
B.
circle
C.
straight line
D.
two intersecting lines
Answer :
square
Solution :
Let the two perpendicular lines be the co-ordinate axes.
Let $$\left( {x,\,y} \right)$$ be the point sum of whose distances from two axes is 1 then we must have
$$\left| x \right| + \left| y \right| = 1\,\,\,\,{\text{or}}\,\, \pm x \pm y = 1$$
These are the four lines $$x+y=1, \,x-y=1, \,-x+y=1, \,-x-y=1$$
Any two adjacent sides are perpendicular to each other. Also each line is equidistant from origin. Therefore figure formed is a square.