Use the Simplify > Factor commandU08MH3 or the Factoring FunctionsFactoring_Functions to factor a number into prime decomposition form.


The prime decomposition (factorization) of a rational number is a product of prime numbers raised to integer (possibly negative) powers.  For example, the prime decomposition of

1234567890/49

is

    2              
 2·3 ·5·3607·3803  
————————————————— 
         2         
        7          


The methods Derive uses to factor numbers include trial division, perfect power testing, Pollard/Brent's ρ (rho), Pollard's p-1, William's p+1, and Lenstra's elliptic curve method.


If Display Steps mode is on when Derive is trying to factor an integer, the part of the integer that remains un-factored and the factoring method being used is displayed on the status line.  You can turn on Display Steps mode using the check box on the Simplification tab of the Options > Mode Settings Command19_L5FP.  For example, turn on Display Steps mode and try factoring the Mersenne number

2^146-1


Factoring a number may take a long time if it has two or more prime factors, each with more than ten decimal digits.  Click on the Calculation Progress dialog box's Abort button or press the Esc key to abort an Simplify > Factor command that is taking too long (for details, see the Simplify Basic commandBQ.NIL).

Created with the Personal Edition of HelpNDoc: Easily create EPub books