Calculating Residuals for Singularities in Complex Functions

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Homework Statement



Calculate the residuals of the following functions in the corresponding singularities:
1) f(z) = z^{2}\exp (\frac{1}{z})
2) f(z) = exp(\frac{-1}{z^{2}})


Homework Equations





The Attempt at a Solution


I can't tell if these functions have poles or not, because I can't calculate lim z \to 0 (z^{m}f(z)), for any natural m. Is it even possible to calculate the residuals this way, or do i need to put the function in Laurent series (which I haven't studied yet)?
 
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Try expressing the exponential by its taylor series.
 
There are two things I don't understand about this problem. First, when finding the nth root of a number, there should in theory be n solutions. However, the formula produces n+1 roots. Here is how. The first root is simply ##\left(r\right)^{\left(\frac{1}{n}\right)}##. Then you multiply this first root by n additional expressions given by the formula, as you go through k=0,1,...n-1. So you end up with n+1 roots, which cannot be correct. Let me illustrate what I mean. For this...

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