This is so obvious that I wonder why it didn't occur to me earlier. When just marking assignments that dealt with the (complex) logarithm and it's branches, it suggests that this area of maths seems rooted among trees. I suppose the 'log' in logarithm doesn't really come from the bit of wood, but it's still a funny thought that it can have different branches... ah, I'm easily amused.
Also in the work I marked, the polynomial 1+z2 had to be factorised. Funnily, the better students who deliver generally nicer work all factored it straightforwardly as (1+iz)(1-iz) while using the form (z+i)(z-i) is a simpler result.
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