Re: help with polynomial solutions

*To*: mathgroup at smc.vnet.net*Subject*: [mg81746] Re: help with polynomial solutions*From*: Szabolcs Horvát <szhorvat at gmail.com>*Date*: Wed, 3 Oct 2007 02:18:34 -0400 (EDT)*References*: <fdt3dv$rqj$1@smc.vnet.net>

Jules P. Aronson wrote: > I could not get mathematica to solve the following class of problems. > > If f(x) and g(x) and two polynomials then a solution to force f(x) to be > equal to g(x) is the equate the coefficients of f(x) to be the same as > those of g(x). For example, > > a x^2 + b x + c == x^2, has a solution, a=1, b=0, c=0. > > If I do the following in mathematica: > > Solve[a x^2 + b x + c == x^2, {a,b,c}] or using Reduce, I do not get the > desired solution. > > Can someone tell how to force mathematica to solve such problems. > Hi, Try Reduce[ForAll[x, a x^2 + b x + c == x^2], {a, b, c}] -- Szabolcs