William J. Cody Jr. has been more influential in the creation of hardware and software for numerical computing than almost anyone else I can think of. This book covers a limited range of functions: square root,log and exponential and power functions, and the trig and hyperbolic functions and their inverses. For all of these, the text discussions are still useful, and for most of them I would happily use the approximations that are included. The most important virtue of this book, however, is the inclusion of careful discussion of how to test subroutines for the elementary functions, complete with suggested programs for doing the testing. A very large number of "broken" elementary function routines shipped with commercial computers over the years would have been repaired before release if the Cody and Waite tests had been used on them. I would give this book 5 stars, rather than 4, except for the fact that the detailed basis for some of the most interesting sets of coefficients is not given; instead, in several places the text remarks cryptically, "The following rational approximations were derived especially for this work."
Because I'm not a wizard like Cody, I would like to know more about how he gets his results. Even so a copy of this book belongs in the library of every college and university math or computing department.
Read more at http://ebookee.org/Software-Manual-for-the-Elementary-Functions-Prentice-Hall-series-in-computational-mathematics-_294059.html#BB826PdRB5xsehct.99