let be open, let \to\mathbb{C}" alt="f\to\mathbb{C}" /> be holomorphic, and let be a zero of order one of . Show that

res

let be open, let \to\mathbb{C}" alt="f\to\mathbb{C}" /> be holomorphic, and let be a simple pole for . Show that

for every holomorphic function \cup z_0 \to \mathbb{C}" alt="g\cup z_0 \to \mathbb{C}" />

any tips?

found it online

http://books.google.ca/books?id=WZX4...sult#PPA175,M1

don't know if that link works since it's rather convoluted, Complex analysis by serge lang page 175

in case anyone else wanted to know this