- Published 2009

We will observe the following notation throughout this course. A function f will, for us, always be from a subset U ⊆ R of the real numbers (usually U is an interval), to the real numbers, and we write f : U → R. U is the domain of the function f (often written dom( f ) = U). The image of the element (number) x ∈ U under the function f is the element f (x) ∈ R. The image of the function f is the union of the images of the elements of U: we will variously write this as Im f = f (U) = { f (x) : x ∈ U}.

@inproceedings{Donaldson2009Math1,
title={Math 140B - Notes},
author={Neil M. Donaldson},
year={2009}
}