1 / | | / ___\ | atan\\/ x / dx | / 0
/ | | / ___\ ___ / ___\ / ___\ | atan\\/ x / dx = C - \/ x + x*atan\\/ x / + atan\\/ x / | /
pi -1 + -- 2
=
0.570796326794897
Use the examples entering the upper and lower limits of integration.