Una pregunta de Yahoo Respuestas
WIRIS desktop includes the possibility to import Derive files. Migrating from Derive files to WIRIS easier than ever, simple open it.
WIRIS cas is an advanced Computer Algebra System including graphical representation in 2D and 3D. Before us there were many. One of the most notorious ones was Derive, in the last years a Texas Instruments product. Since June 29th 2007 Texas Instruments did no longer sell Derive in most of the countries.
WIRIS team has been working on an import feature for Derive files. That is, the new release of WIRIS desktop includes an option to import files with Derive extensions mth and dfw. The import process converts Derive commands into WIRIS commands. Different programs have different approaches to the same problems. Converting files from one to another is always complex task. We obtain a perfect matching for 80% of expressions converting Derive to WIRIS files.
Sebastian Garth wrote in sci.math (his original article is here) that an integer number n is prime iff
The double module makes it such a weird statement that I just had to check it... and it seems to be true!
Just write your prime candidate and click on the = sign:
The above program is useful only for n up to 2,000 , since computing the powers results in huge numbers and it runs ut of time. Now, if we compute the powers modulo n·(n+1)/2 from the beginning, we can save a lot of time; this other program can go up to n=250,000: