Correct Answer - `log sqrt(2)` sq. units
Intergrating along x-axis, we get
`A=overset(1)underset(0)int(cot^(-1)x-tan^(-1)x)dx=overset(1)underset(0)int((pi)/(2)-2tan^(-1)x) dx`
Intergrating a long y-axis, we get
`A=2overset(pi//4)underset(0)int x dy=2.overset(pi//4)underset(0)inttan y dy=[ log (secy )]_(0)^(pi//4)`
`=log sqrt(2)` sq. units