- #1
Mathmos6
- 81
- 0
Homework Statement
Hi all,
I've just calculated the first three nonzero terms of the Laurent series of 1/(cos(z)-1) in the region |z|<2pi, and now I've been asked to 'find the three non-zero central terms of the Laurent expansion valid for 2pi<|z|<4pi' - firstly, what does it mean by 'central terms', and secondly, how do I calculate an expansion valid in an annulus? I have no idea how to expand except for in a ball |z-a|<r, unless I'm being slow here (very possible)! Perhaps the second question will answer the first for me anyway - thanks very much for the help,
M