ISO/IEC 29794-4:2017 Equation 12 is well known to be susceptible to rounding errors, better, more stable formulations exist. The most stable method would be SVD (Singular Value Decomposition). A sufficient alternative may be the formula given under “Avoiding loss of significance” in https://en.wikipedia.org/wiki/Quadratic_equation
Source: Comment DE-068 from ISO/IEC JTC 1/SC 37/WG 3 N 1416 (Clause 5.2.2.2)
Consider changing this equation.
ISO/IEC 29794-4:2017 Equation 12 is well known to be susceptible to rounding errors, better, more stable formulations exist. The most stable method would be SVD (Singular Value Decomposition). A sufficient alternative may be the formula given under “Avoiding loss of significance” in https://en.wikipedia.org/wiki/Quadratic_equation
Source: Comment DE-068 from ISO/IEC JTC 1/SC 37/WG 3 N 1416 (Clause 5.2.2.2)