Does anyone know of an online calculator/tool that allows you to calculate integrals in the complex number set over a path?
I've searched in the standard websites (Symbolab, Wolfram, Integral Calculator) and none of them has this option for complex calculus (they do have, as it has been pointed out, regular integration in the complex plain, but none has an option to integrate over paths).
Wolfram alpha sure can work with complex integrals. Here I'm integrating $e^{i \theta}$ with respect to $\theta$, between $0$ and $2 \pi$:
https://www.wolframalpha.com/input/?i=Integrate%5Be%5E%28I+theta%29%2C%7Btheta%2C0%2C2*Pi%7D%5D