The archive file quartic.zip contains the files:

readme.txt | this file of general description |

quartic.f90 | the complete source code |

To compile this program for your computer, use the command

gfortran quartic.f90 -o quartic.exe

Linux and Macintosh users may prefer to omit the .exe on the file name.

This program computes the solution to the polynomial equation

a*x**4 + b*x**3 + c*x**2 + d*x + e = 0

with real coefficients.

The program asks for the coefficients of each term of the polynomial to be solved. If you are solving a cubic, answer zero to the question "What is the coefficient of the quartic term?"

It is best if you compile the program using your Fortran compiler with the appropriate options for your computer system. If you do not wish to do this, you may download quarticexecs.zip containing the files quartic.exe, quartic.mac, and quartic.lnx, the executable program for Windows, Mac OS X, and Linux, each compiled generically for an Intel CPU.