HP 40gs User Manual page 229

hp40g+.book Page 47 Friday, December 9, 2005 1:03 AM
DIVIS
EULER
FACTOR
GCD
Computer Algebra System (CAS)
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.
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.
Decomposes an integer into its prime factors.
Example
Typing:
FACTOR(90)
gives:
2
2·3 ·5
Returns the greatest common divisor of two integers.
Example
Typing:
GCD(18, 15)
gives:
3
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