Solution of $\int_0^{\infty} \frac{\arctan(x)-\arctan(2x)}x\mathrm dx$ : Why Wolfram Alpha shows a different answer than mine?
Evaluate the improper integral $\int_{0}^{\infty}{f(x)-f(2x)\over x}dx$, where $\lim_{x \to \infty} f(x) = L$