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+--- Thread: find the lowest common denominator (/thread-9938.html)
find the lowest common denominator - Hamada-77 - 01-15-2018 10:25 AM
hello
how can i find the lowest common denominator of two numbers with Hp prime ?
thanks
RE: find the lowest common denominator - Didier Lachieze - 01-15-2018 12:53 PM
I'm not sure there is a build-in function providing the lowest common denominator.
So here is a small program doing that:
Code:
EXPORT LCD(N,M)
BEGIN
LOCAL l:={};
l:=INTERSECT(mat2list(idivis(N)),mat2list(idivis(M)));
RETURN l(MIN(SIZE(l),2));
END;RE: find the lowest common denominator - Joe Horn - 01-15-2018 12:59 PM
(01-15-2018 12:53 PM)Didier Lachieze Wrote: I'm not sure there is a build-in function providing the lowest common denominator.
There is: it's the lcm function (lowest common multiple). In CAS, it works on integers of any length.
lcm(12,18) --> 36
1/12+1/18 --> 5/36
It also works on polynomials, not just integers.
RE: find the lowest common denominator - Didier Lachieze - 01-15-2018 01:20 PM
Good point, I misunderstood the request as beeing for the lowest common divisor.
RE: find the lowest common denominator - john gustaf stebbins - 01-16-2018 12:31 AM
I'm getting to go through this basic math with my kids now.
I think the least common divisor can be found with the "1" function.
;^)
On the 50g, this was actually function of sort, at least a token so that this commonly used number parsed faster than a number literal. Don't know that they have done the same with the Prime.
-jgs