Get denominator with hold=True

Anonymous

I am struggling to get the denominator of an expression defined with hold=True.

The expression is a quotient with a common factor in the numerator and denominator.

I don't want the common factor to be cleared out.

Example:

sage: t2 = x.mul(1 / (x^2 - x), hold=True)

sage: t2
x/(x^2 - x)

sage: t2.denominator()
x - 1


This results in x - 1 instead of x*(x - 1) or x^2 - x.

Is there any other way to obtain x^2 - x?

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To find out about the possible extra arguments of a method you could access its documentation with a question mark. Here

sage: t2.denominator?
Docstring:
Return the denominator of this symbolic expression

INPUT:

* "normalize" -- (default: "True") a boolean.

If "normalize" is "True", the expression is first normalized to
have it as a fraction before getting the denominator.

If "normalize" is "False", the expression is kept and if it is not
a quotient, then this will just return 1.


Hence in your situation you could do

sage: t2.denominator(normalize=False)
x^2 - x

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Thx. ๐๐๐

( 2021-04-26 08:37:24 +0200 )edit