For z=1, doesn't the function evaluate to 11+10i+10i-11=20i ?
and for z=-1, f(z)=11-10i-10i-11=-20i ?
So I don't see how 1 and -1 are roots?
What am I missing?
When I use Wolfram Alpha, I do get 10 complex solutions (5 conjugate pairs), which do seem to all have magnitude =1. But I expect Danish is asking for an analytical solution.
re(2): Possible proof - question?
