Re: Possible bug concerning a limit computation

*To*: mathgroup at smc.vnet.net*Subject*: [mg71122] Re: Possible bug concerning a limit computation*From*: Jean-Marc Gulliet <jeanmarc.gulliet at gmail.com>*Date*: Thu, 9 Nov 2006 03:37:20 -0500 (EST)*Organization*: The Open University, Milton Keynes, UK*References*: <eish78$nrd$1@smc.vnet.net>

geo_topos wrote: > Hello everyone, > I don't know if this is the right place to post this, but here it goes. > I am a high-school math teacher from greece. I was working with my > students on the limit: > > Limit[ (Sqrt[7x^4+6x+5] - Sqrt[7x^4+3x+3]) * Sqrt[63x^2-5x+20, x-> > Infinity] > > The result we got for that is 9/2. Mathematica 4.0 will produce the > opposite result: -9/2. Mathematica 5.2 agrees with the positive result In[1]:= Limit[(Sqrt[7*x^4 + 6*x + 5] - Sqrt[7*x^4 + 3*x + 3])* Sqrt[63*x^2 - 5*x + 20], x -> Infinity] Out[1]= 9 - 2 In[2]:= $Version Out[2]= 5.2 for Microsoft Windows (June 20, 2005) Regards, Jean-Marc