The archive file quartic.zip contains the files:
| readme.txt | this file of general description |
| quartic.f90 | the complete source code |
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?"