[Gerd]

Hello,

To calculate the dynamic frequency response in filter theory I need the solution or a substitution for the following Integral:

Integrate[Log[Cos[ax/(1+a^2x^2)–ArcTan[ax]]],x]

I could not find any. You will get 10% of my Nobel Prize if I get one for the correct solution

Gerd+

[C1ay]

Have you tried the Integrator? It's a web interface to Mathematica.

[Gerd]

Hello!
I get the input as output from Mathematica. That means it cannot find a solution.
Gerd+