mersenneforum.org - View Single Post - Calculator that can factor and find exact roots of polynomials

alpertron · 2019-11-13, 20:15

Quote:

Originally Posted by Dr Sardonicus

I tried the minimum polynomial for $2\cos(\frac{2\pi}{11})$ ,

x^5 + x^4 - 4*x^3 - 3*x^2 + 3*x+ 1

and the answer was a bit hard to read. I'm not sure whether it was right.

The answer shown by the application is wrong. I unchecked Pretty Print, copied the output to Notepad++, deleted all (xxx digits) and spaces, replaced i by I and finally copied that to gp. All five roots shown are non-real, so something is not good.

Another error is that the digits in group is not working. The program always shows groups of 6 digits.

I will work on that.