I was working through Griffiths' for quantum mechanics, and I came across some problems where we have to calculate expectation values. This motivated me to ask the following question: https://math.stackexchange.com/q/4480981/. I don't understand why this question was downvoted. It's not a homework problem, it seems plausible that such a trick might exist, and I explained the question clearly. Furthermore, I am really getting quite frustrated by people on stack exchange (physics and math) downvoting posts of new users and giving no justification as to why. How are new users supposed to improve?