Find the area of the region enclosed by the curve y = 1 1+x2 and it’s asymptote. PLEASE EXPLAIN THE ALL THE SUMS BY STEP BY STEP SIR

This curve approaches to y = 0 as x approaches infinity. Hence, y=0 is its asymptote.
Hence, now find out the area under this curve.
Area = 2 X Integral of y(Limits 0 to inf. )
A = 2 . (tan^(-1)x) (limits 0 to inf. )
A = 2 . pi/2
A = pi units
Thanks
Bharat Bajaj
IIT Delhi
askiitians faculty