# Tag Archives: Jenkins-Traub

## Solving Quadratic, Cubic, Quartic and higher order equations; examples

A previous post presented a spreadsheet with functions for solving cubic and quartic equations, and this has been extended with another function solving higher order polynomials.  The functions are actually very easy to use, but the documentation in the spreadsheets is quite brief, … Continue reading

Posted in Arrays, Excel, Link to Python, Maths, Newton, UDFs, VBA | | 12 Comments

## Polynomial Update

Following a comment here: Solving cubic and quartic equations with Excel the Quartic and CubicC User Defined Functions (UDFs) have been amended to fix a problem occurring with some combinations of coefficients. The updated spreadsheet (including full open source code) can be … Continue reading

Posted in Excel, Maths, Newton, UDFs, VBA | | 12 Comments

Today’s download provides analytic solutions to polynomial equations up to fourth order (that is quadratic, cubic and quartic equations) and an iterative method to solve equations of higher order.  All these functions are found in the download file: http://interactiveds.com.au/software/Polynomial.zip The … Continue reading

Posted in Excel, Maths, Newton, UDFs, VBA | | 1 Comment

## Linest, NPV, IRR and solving polynomials

In a comment on Using LINEST for non-linear curve fitting Lori Miller posted a formula that found the coefficients fitting a cubic polynomial curve to a set of data, then solved the resulting equation to find the X value for a given … Continue reading

Posted in Excel, Maths, Newton, UDFs, VBA | | 3 Comments

## Evaluating higher order polynomials …

… and a better solution for quadratics. Having written a better solver for high order polynomials, that raises a few other issues.  The error in the roots found by the RPolyJT was checked by simply substituting each root as the … Continue reading

Posted in Excel, Maths, Newton, UDFs, VBA | | 4 Comments