Hi Debadutta,

Let 1≤x<2. So [x] = 1.

And [y]^2 = 1 or [y] = ± 1.

means 1≤y<2 or -1≤y<0.

So in this region you will have two squares each of area 1 unit.

So when 1≤x<2 the area will be 2 sq units.

Similarly when 2≤x<3 the area = 2 sq untis

And 3≤x<4, area = 2 sq untis.

and 4≤x<5, area = 2 sq units.

So total area in the region would be 2+2+2+2 = 8 sq untis.

Regards,

Ashwin (IIT Madras).