determine if expression is polynomial P(x,y/Q(x,y)
Subject: determine if expression is polynomial P(x,y/Q(x,y)
From: Richard Fateman
Date: Sat, 25 Feb 2012 06:25:54 -0800
On 2/25/2012 6:02 AM, nijso beishuizen wrote:
> Dear all,
>
> The problem I am dealing with now is related to my previous question
> about determining if an expression is polynomial. I now want to
> determine if an expression is of the form P(x,y)/Q(x,y), where P and Q
> are bivariate polynomials in x and y. Like my previous problem, it
> should also accept expressions that contain e.g. sin(x) but then
> return something meaningful when it is not a polynomial.
>
> I think this can be done by putting the expression in CRE form and
> determine the numerator and denominator using Q:ratdenom(expr) and
> P:ratnumer(expr).
> If I call showratvars(Q), will Q then always be a polynomial in x and
> y if it returns [x,y]?
>
>
> Regards,
> Nyso
>
Is sin(x)^2 +cos(x)^2 +x supposed to be a polynomial in x for your
purposes?