Quotient-Difference Algorithm and Code for Cubic Polynomials with Computational Implementation

This article explores the computational intricacies of H. Rutishauser’s Quotient-Difference (Q-D) algorithm and C programming code, a revolutionary advancement in polynomial analysis. Our specific focus is on cubic polynomials featuring absolute, distinct non-zero real roots. Emphasizing the algorithm’s distinctive capability to simultaneously approximate all zeros independently of external data. Notably, it proves invaluable in diverse domains, such as determining continuous fraction representations for meromorphic functions and serving as a powerful tool in complex analysis for the direct localization of poles and zeros. To bring this innovation into practice, the article introduces a meticulously crafted C language program, complete with a comprehensive algorithm and flowchart. Supported by illustrative examples, this implementation underscores the algorithm’s robustness and effectiveness across various real-world scenarios.