HP 40gs hp 40gs_user's guide_English_E_HDPMSG40E07A.pdf - Page 229

hp40g+.book Page 47 Friday, December 9, 2005 1:03 AM DIVIS Gives the divisors of an integer. Example Typing: DIVIS(12) gives: 12 OR 6 OR 3 OR 4 OR 2 OR 1 Note: DIVIS(0) returns 0 OR 1. EULER Returns the Euler index of a whole number. The Euler index of n is the number of whole numbers less than n that are prime with n. Example Typing: EULER(21) gives: 12 Explanation: {2,4,5,7,8,10,11,13,15,16,17,19} is the set of whole numbers less than 21 and prime with 21. There are 12 members of the set, so the Euler index is12. FACTOR Decomposes an integer into its prime factors. Example Typing: FACTOR(90) gives: 2·32·5 GCD Returns the greatest common divisor of two integers. Example Typing: GCD(18, 15) gives: 3 Computer Algebra System (CAS) 14-47