Range Reduction

Abstract

The algorithms presented in the previous chapters for evaluating the elementary functions only give a correct result if the argument is within a given bounded interval. To evaluate an elementary function f(x) for any x, one must find some “transformation” that makes it possible to deduce f(x) from some value g(x*), where

• x*, called the reduced argument, is deduced from x;

• x* belongs to the convergence domain of the algorithm implemented for the evaluation of g.