Re: transposing an equation

*To*: mathgroup at smc.vnet.net*Subject*: [mg26252] Re: [mg26234] transposing an equation*From*: Maarten.vanderBurgt at icos.be*Date*: Sun, 10 Dec 2000 00:19:29 -0500 (EST)*Sender*: owner-wri-mathgroup at wolfram.com

Christopher, try In[5]:= Solve[y == a x + b x^2 + c, x] Out[5]= {{x -> (-a + Sqrt[a^2 - 4*b*c + 4*b*y])/(2*b)}, {x -> -((a + Sqrt[a^2 - 4*b*c + 4*b*y])/(2*b))}} And you will see there is no general way to re-write y = a x^2 + b x + c as x = Ay^2 + By + C. Except for some special cases there will be a Sqrt[y] in the solution. Maarten van der Burgt Leuven, Belgium "Christopher Deacon" <cdeacon at physics.mun.ca> on 06-12-2000 08:16:20 AM Subject: [mg26252] [mg26234] transposing an equation Suppose y=a x^2+b x +c. How can I get Mathematica to solve for x (i.e., x=Ay^2+By+C) and give me the values for the constants A,B,C? Chris -- +-----------------------------+----------------------------+ | Christopher Deacon | (709) 737-7631 | Dept of Physics and Physical| cdeacon at physics.mun.ca | Oceanography | Memorial University of Nfld +----------------------------+-----------------------------+ | http://www.physics.mun.ca/~cdeacon +----------------------------------------------------------+