What is the point of analytic continuation? Surely if a function is not valid in some of the complex plane and you change it so it becomes valid, you've created a new function, telling you nothing about the original one.

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- November 30th 2010, 12:30 PMRudolfAnalytic Continuation
What is the point of analytic continuation? Surely if a function is not valid in some of the complex plane and you change it so it becomes valid, you've created a new function, telling you nothing about the original one.

- November 30th 2010, 12:45 PMtonio

Uh? Take for example the series . This series converges

and defines an analytic function within the unit disk, but we can continue its definition as to the whole

plane except at the point .

There are other much more important examples, say the zeta Riemann function (see http://numbers.computation.free.fr/C...neralities.pdf , for ex.). Google it.

Tonio - November 30th 2010, 02:53 PMwonderboy1953
- November 30th 2010, 03:00 PMRudolf
I think so:

x/sin x, at the point x = 0.