substitution does actually work, the thing is that you need to do some algebra first.
so put then the integral becomes now back substitute.
I don't know where to begin! Substitution definitely does not work. Integration by parts & partial fractions do not seem to work either.
I cannot factor the denominator. I get imaginary roots!
How do I proceed with this type of problem? Thanks. PS: I suspect it has something to do with the arctan function!