# Math Help - Laurent Series

1. ## Laurent Series

Hello, i got this question in a exam:

Get the Laurent Series of

${\sqrt{(z-1)(z-2)}}$

i think he said we could do the expansion at the point of our choice

can you help me out?

2. Originally Posted by PanZerOlas
Hello, i got this question in a exam:

Get the Laurent Series of

${\sqrt{(z-1)(z-2)}}$

i think he said we could do the expansion at the point of our choice

can you help me out?
Notice that $(z-1)(z-2) = z^2 - 3z + 2 = z^2 - 3z + \tfrac{9}{4} - \tfrac{9}{4} + 2 = \left( z - \tfrac{3}{2} \right)^2 + \tfrac{17}{4}$.
Thus, I think the most conveint point is $\tfrac{3}{2}$ to exand the series.

Now, you can almost finish the problem by applying the binomial series.