A Programmer's Introduction to Mathematics

I don't know whether this book is good or not, but I am a bit disappointed that its very first mathematical definition (that appears on p.6) is already wrong:

  > Definition 2.1. A single variable polynomial with real coefficients is a function f that takes a real number as input, produces a real number as output, and has the form f(x) = a_0 + a_1x + a_2x^2 + ... + a_nx^n, ...

It is fine not to distinguish between “polynomial” and “polynomial function” in a high school textbook, but for a book at college level, I think we should expect a higher standard.