To Solve a Real Cubic Equation

摘要

A program to solve a real cubic equation efficiently and as accurately as the data deserve is not yet an entirely cut-and-dried affair. An iterative method is the best found so far. This method plus some other issues, like accuracy, scaling, preconditioning and testing, are discussed in these notes in enough detail to convey an impression of what Numerical Analysis is about. Keywords: QBC computer program, Newton's iterations. (kr)