Re: PolynomialQ (wrong) behavior ?

*To*: mathgroup at smc.vnet.net*Subject*: [mg19231] Re: PolynomialQ (wrong) behavior ?*From*: "Allan Hayes" <hay at haystack.demon.co.uk>*Date*: Wed, 11 Aug 1999 02:06:47 -0400*References*: <7oojic$i2c@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

Drago Ganic <drago.ganic at in2.hr> wrote in message news:7oojic$i2c at smc.vnet.net... > 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 > Drago: Formally, f is a polynomial in Sin[x] with constant term f. Coefficient[ 2x + 1, Sin[x] , 0] 1 + 2 x CoefficientList[ 2x + 1, Sin[x] ] {1 + 2 x} Also note Series[2x + 1 + 3(Sin[x] + 1)^4, { Sin[x], 0, 3}] // Normal 4 + 2*x + 12*Sin[x] + 18*Sin[x]^2 + 12*Sin[x]^3 Allan --------------------- Allan Hayes Mathematica Training and Consulting Leicester UK www.haystack.demon.co.uk hay at haystack.demon.co.uk Voice: +44 (0)116 271 4198 Fax: +44 (0)870 164 0565