This content is licensed under Creative Commons Attribution/Share-Alike License 3.0 (Unported). That means you may freely redistribute or modify this content under the same license conditions and must attribute the original author by placing a hyperlink from your site to this work https://planetcalc.com/7765/. Also, please do not modify any references to the original work (if any) contained in this content.
The calculator solves real polynomial roots of any degree univariate polynomial with integer or rational terms. The calculator factors an input polynomial into several square-free polynomial, then solves each polynomial either analytically or numerically (for 5-degree or higher polynomials). A function graph is plotted to illustrate the polynomial solution.
N-degree polynomial real root calculation algorithm
- Check whether the input polynomial even or odd - the polynomial is even if f(x) = f(-x), the polynomial is odd if f(x)=-f(-x).
- Factor the polynomial into square-free polynomials with Yun algorithm Squarefree polynomial factorization.
- Every n-degree polynomial obtained is solved analytically if n<5:
- For 1st-degree - the root is the negative free term divided by the x coefficient
- 2nd degree is solved by Solution of quadratic equation
- 3rd degree: Cubic equation
- 4th degree: Quartic equation solution
- Use numeric methods If the polynomial degree is 5 or higher
- Isolate the root bounds by VAS-CF algorithm: Polynomial root isolation. Find the roots in the positive field only if the input polynomial is even or odd (detected on 1st step)
- For each isolation bound find the approximate root value using numeric method: Bisection method
- Add the negative roots to the result set if the input polynomial is even or odd.