The integral of (1/(1+e^x)) dx can be approached using substitution, specifically letting u = 1 + e^x, which simplifies the integral to a form suitable for partial fraction decomposition. Some participants suggest multiplying by e^-x to facilitate the substitution, leading to a simpler integral. There is debate over the necessity of partial fractions, with some arguing that it can be avoided depending on the substitution used. The discussion highlights common misunderstandings about logarithmic integration rules and the importance of correctly differentiating expressions. Overall, the integral can be evaluated effectively with the right substitutions and methods.