TY - BOOK ID - 135815744 TI - Dual sets of envelopes and characteristic regions of quasi-polynomials AU - Cheng, S. S. AU - Lin, Yizhong PY - 2009 SN - 1282443070 9786612443077 9814277282 PB - Hackensack, NJ : World Scientific, DB - UniCat KW - Functions, Special. KW - Polynomials. UR - https://www.unicat.be/uniCat?func=search&query=sysid:135815744 AB - Existence and nonexistence of roots of functions involving one or more parameters has been the subject of numerous investigations. For a wide class of functions called quasi-polynomials, the above problems can be transformed into the existence and nonexistence of tangents of the envelope curves associated with the functions under investigation. In this book, we present a formal theory of the Cheng-Lin envelope method, which is completely new, yet simple and precise. This method is both simple - since only basic Calculus concepts are needed for understanding - and precise, since necessary and s ER -