# Definition of a differentiable function

1. Dec 16, 2006

### Dragonfall

I need to know the definition of a differentiable function at a point in Banach spaces, my notes has a certain ambiguity and I can't find a book with the definition. Thanks.

2. Dec 16, 2006

### quasar987

3. Dec 16, 2006

### Dragonfall

The wiki ones do not correspond (though I'm sure they are equivalent) to what we use. I found my definition from some obscure source, but thanks anyway.