In upper level math courses it can be sort of relieving to see the word "show" as opposed to "prove" every once in a while. The difference has always been pretty clear to me, but I had a case where my professor did not share my understanding of the word "show".
This was some months ago, and it was on the very first homework for complex analysis. We had reviewed some basic set theory, and obviously that was part of the homework. I can't remember exactly what it was, but it had to do with set operations, subsets and showing that they were in fact subsets. When he went over this in class he just drew diagrams - that's fine, I wasn't expecting him to go over every aspect of these proofs that we should all be familiar with. So on the homework I did exactly what he did in class. It was a three part question, and I just drew diagrams for each one. After all, it said "show". Anyway, that was one of only five questions and he just marked the whole thing wrong.
Has anyone else ran into a similar problem like this before? Do you think I was actually wrong to do that?
