In this case, f[x] is not computed and, thus, Mathematica returns no output (delayed assignment). The form f[x] := ... should be used when Mathematica cannot evaluate f[x] unless x is a particular value, as with recursively defined ...
Author: Martha L. Abell
Publisher: Academic Press
Mathematica by Example, 4e is designed to introduce the Mathematica programming language to a wide audience. This is the ideal text for all scientific students, researchers, and programmers wishing to learn or deepen their understanding of Mathematica. The program is used to help professionals, researchers, scientists, students and instructors solve complex problems in a variety of fields, including biology, physics, and engineering. Clear organization, complete topic coverage, and accessible exposition for novices Fully compatible with Mathematica 6.0 New applications, exercises and examples from a variety of fields including biology, physics and engineering Includes a CD-ROM with all Mathematica input appearing in the book, useful to students so they do not have to type in code and commands