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Prime Factors, LCM and GCF

Finding Prime Factors:

factor(rationalNumber) returns the rational number factored into primes.

If you are simply trying to decide if a number is prime, use isPrime( ).

Example:  

Find the prime factors of 72.

From a Calculator Page:
MENU - #2 Number - #2 Factor

factorfactor

NOTE: According to the manual, the computing time for composite numbers grows exponentially with the number of digits in the second-largest factor. Factoring a 30-digit integer could take more than a day and a 100-digit number could take more than a century.


Finding the Least Common Multiple (LCM):

lcm(Number1, Number2)
will return the least common multiple of the two numeric values.
Only accepts two values at a time.

Example:  
Find the LCM for 10, 15, and 45.

From a Calculator Page:
MENU - #2 Number
#3 Least Common Multiple
 

Since LCM can only accept two entries at a time, find the LCM of the first two values, and then find the LCM of your answer and the third value.

prime2

 

Finding the Greatest Common Factor (GCF):

gcd(Number1, Number2)
will return the greatest common divisor of the two numeric values.
Only accepts two values at a time.

NOTE:  The calculator refers to the GCF as the GCD, greatest common divisor.

Example:  
Find the GCF (or GCD) for 12, 24, and 32.

From a Calculator Page:
MENU - #2 Number
#4 Greatest Common Divisor 

Since GCD can only accept two entries at a time, find the GCD of the first two values, and then find the GCD of your answer and the third value.

prime3

1

 


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