oo / | | atan(x) | ------- dx | 2 | 1 + x | / o
Integral(atan(x)/(1 + x^2), (x, o, oo))
Let .
Then let and substitute :
The integral of is when :
Now substitute back in:
Add the constant of integration:
The answer is:
/ | 2 | atan(x) atan (x) | ------- dx = C + -------- | 2 2 | 1 + x | /
2 2
atan (o) pi
- -------- + ---
2 8
=
2 2
atan (o) pi
- -------- + ---
2 8
-atan(o)^2/2 + pi^2/8
Use the examples entering the upper and lower limits of integration.