Hi everyone,
Can you tell me how to integrate the following equation?
\int\frac{1}{x^2 + 1} \ dx
I've tried the substitution method, u = x^2 + 1, du/dx = 2x. But the x variable is still exist.
Also, the trigonometry substitution method, but the denominator is not in \sqrt{x^2 + 1}...