homeworks and attendance quizzes for kang

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+Q1) Find power series
+
+f(z) = e^{-z}/z^2 for 0<|z|<\infty
+
+e^{-z} = 1 - z + z^2/2! - z^3/3! + z^4/4! ...
+f(z) = 1/z^2 - 1/z + 1/2! - z/3! + z^2/4! ...
+
+Q2)
+
+f(z) = {1+2z^2 \over z^3 + z^5} |z|<1
+     = {1 \over z^3(1+z^2)} + {2\over z(1+z^2)}
+
+{1\over (1+z^2)} = 1 - z^2 + z^4 - z^6 ...
+
+{1\over z^3(1+z^2)} = 1/z^3 - 1/z + z - z^3 ...
+{2\over z(1+z^2)} = 2/z - 2z + 2z^3 - 2z^5 ...
+
+f(z) =
+1/z^3 + 2/z - 1/z - 2z + z + 2z^3 - z^3 - 2z^5 ...