Area of the parallelogram formed by the lines y=mx, y=mx+1, y=nx and y=nx+1 equals [2001]
(4)
The vertices, O(0,0), A(1m-n,mm-n), B(0,1)
Area (parallelogram OABC)=2×area (∆OAB)
=2×12|[0(mm-n-1)+1m-n(1-0)+0(0-mm-n)]|
=1|m-n|