Expand the following functions in a Laurent series, giving a closed formula for the coefficient an (Hint: If you combine differently shifted powers, for example bnzn and ckzk+1, you have to substitute n=k+1 and treat the term n=0 separately) a) f(z)=(z1)(z2)1 around z0=0 in all annular regions. b) f(z)=z2+1z around z0=i in the annular region zi