Re: PolynomialQ (wrong) behavior ?
- To: mathgroup at smc.vnet.net
- Subject: [mg19228] Re: [mg19199] PolynomialQ (wrong) behavior ?
- From: "Andrzej Kozlowski" <andrzej at tuins.ac.jp>
- Date: Wed, 11 Aug 1999 02:06:45 -0400
- Sender: owner-wri-mathgroup at wolfram.com
The function PolynomialQ is pretty simple minded. The expression 2x+1 is considered as a constant polynomial in x. A little more controversially, it is also considered as a constant polynomial in Sin[x], since it does not explicitely involve Sin[x] as variable. This is quite consistent with the behaviour of the derivative: In[1]:= D[2x + 1, y] Out[1]= 0 In[2]:= D[2x + 1, Sin[x]] Out[2]= 0 -- Andrzej Kozlowski Toyama International University JAPAN http://sigma.tuins.ac.jp http://eri2.tuins.ac.jp ---------- >From: "Drago Ganic" <drago.ganic at in2.hr> To: mathgroup at smc.vnet.net >To: mathgroup at smc.vnet.net >Subject: [mg19228] [mg19199] PolynomialQ (wrong) behavior ? >Date: Tue, Aug 10, 1999, 8:52 AM > > Hi, > > f = 2x +1 > > PolynomialQ [ f, x ] > True > > That's OK. But why the following > > PolynomialQ [ f, y ] > True > > PolynomialQ [ f, Sin[x] ] > True > > Greetings, > Drago Ganic > > > > > > >