The reason I ask the aforementioned question is because I came across the expectation values of operators in Quantum Mechanics. And part of the computation involves integrating a function of the complex conjugate of x with respect to dx. So as an example let's say I have: ∫ sin (x*) dx where the * denotes the complex conjugate. How would I do it? (I would post an attempt to solve it but I have no idea whether to even treat the x* as a constant, or variable or.....something). Thank you in advance for any help you may provide.