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## Homework Statement

Suppose f is analytic inside and on the unit circle |z|=1. Prove that if |f(z)|[tex]\leq[/tex]M for |z|=1, then |f(0)|[tex]\leq[/tex]M and |f'(0)|[tex]\leq[/tex]M.

Finally, what estimate can you give for |f^n(0)|?

## Homework Equations

This problem is in a section dealing with Cauchy's Integral Formula and it's generalized form.

http://en.wikipedia.org/wiki/Cauchy_integral_formula

## The Attempt at a Solution

Im not quite sure how to get started here. Obviously Cauchy's formulas apply to our function f considering its analiticity. I guess I don't really understand the if part of our statement. IE if |f(z)|[tex]\leq[/tex]M for |z|=1. The magnitude of the function f is bounded??? I don't know what it means "for |z|=1." I'm missing something here. A nudge in the right direction would be appreciated. Thanks!