20080314, 22:00  #1 
Mar 2008
17 Posts 
is this prime?
IM NOT SURE IS THIS NUMBER PRIME?

20080314, 22:07  #2  
Account Deleted
"Tim Sorbera"
Aug 2006
San Antonio, TX USA
17×251 Posts 
Please find it on your own. I know it, and it's easy to find, you really don't need to post here for this. I'll repeat my instructions, just to be sure you have them:
Quote:
Quote:
Pari/GP can find the primality of a number that size easily, use isprime(x). 

20080314, 22:16  #3 
Mar 2008
17 Posts 
ok 'my problem is that it doesnt work
i put a number in and instead of writing if its prime or not it writes the order(if i write foe example 4 in the first time it will writ me 1)

20080314, 22:29  #4  
Account Deleted
"Tim Sorbera"
Aug 2006
San Antonio, TX USA
17×251 Posts 
Quote:
(after running the same command again) %2 = 0 Is this the sort of thing you're talking about? It's saying "%1", a reference for you to use in later formulas to reference this output, "= 0" meaning not prime (0 for not prime, 1 for prime). If you're saying it prints something like (assuming you're trying to check 11 for primality) "%1 = isprime11", then you need to put the parentheses around it so it knows you're telling it a command and not saying a name of a new variable or something. Edit: Try typing isprime(11) and see if it returns "%1 = 1". Last fiddled with by MiniGeek on 20080314 at 22:31 

20080314, 22:34  #5 
Mar 2008
17 Posts 
no it returns %6=(11)
it says six because its the 6 number i tried 
20080314, 22:36  #6 
Mar 2008
17 Posts 
never mind it works thanx but it doesnt check big numbers
(more then a 100 digits also) Last fiddled with by n1994 on 20080314 at 22:37 
20080314, 22:43  #7  
Account Deleted
"Tim Sorbera"
Aug 2006
San Antonio, TX USA
17×251 Posts 
Quote:


20080314, 22:45  #8 
Mar 2008
21_{8} Posts 
no im doing what you said isprime(x) but it "cuts" the nuber where the programs end instead of writing the hole number it makes it shorter.

20080314, 23:01  #9 
Account Deleted
"Tim Sorbera"
Aug 2006
San Antonio, TX USA
17·251 Posts 

20080314, 23:08  #10 
Mar 2008
17 Posts 
no that works fine now it returns 1 but if u put a big number it makes it shorter

20080314, 23:11  #11 
Account Deleted
"Tim Sorbera"
Aug 2006
San Antonio, TX USA
10AB_{16} Posts 
So isprime(11) returns "1" but if you paste a number instead of typing "11", it returns the full number? Try copying "11", then doing it just like you'd paste a larger number (making sure the command stays "isprime(11)") and double check that it returns "1". Then copy a large number, making sure you have "isprime(" before it and then typing ")" after it, and see if it returns 0 or 1 or something else.

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