simple trouble with the Cauchy formula...

hi everyone,

would someone explain how to handle the first term in the 'higher-order' version of the Cauchy formula for n=1, when f(z) is replaced by its power series expansion? I'm reading "The Road to Reality" by Penrose and at the bottom of page 127, he says it's simple to show that when you substitute f(z) with its power series expansion, you get f'(0), i.e. for n=1. All terms work out for me except the first term, which is based on just the constant "a-sub-zero" in the power series expansion - this term seems to go to infinity when i deal with it, yet it must reduce to zero for the formula to actually work. Can you show me how to get this first term to "disappear"?

regards,

js.