Re: Calculating derivate in Mathematica 9 giving wrong

*To*: mathgroup at smc.vnet.net*Subject*: [mg131416] Re: Calculating derivate in Mathematica 9 giving wrong*From*: "Louis Talman" <talmanl at gmail.com>*Date*: Wed, 3 Jul 2013 22:01:02 -0400 (EDT)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com*Delivered-to*: l-mathgroup@wolfram.com*Delivered-to*: mathgroup-outx@smc.vnet.net*Delivered-to*: mathgroup-newsendx@smc.vnet.net*References*: <20130703090146.A8EAD6AD9@smc.vnet.net>

Asking for the derivatives of the same expressions might give you the same, or at least equivalent, results. On Wed, 03 Jul 2013 03:01:46 -0600, James <jhlawley at gmail.com> wrote: > In[5]:= D[(x^2 - 2)/(x^3 + 6), x] > Out[5]= -((3 x^2 (-2 + x^2))/(6 + x^3)^2) + (2 x)/(6 + x^3) > That is from Mathematica 9. > The wolfram alpha site and my textbook give this answer: > d/dx((x^2+x-2)/(x^3+6)) = (-x^4-2 x^3+6 x^2+12x+6)/(x^3+6)^2 > Please tell me what I am doing wrong. --Louis A. Talman Department of Mathematical and Computer Sciences Metropolitan State University of Denver <http://rowdy.msudenver.edu/~talmanl>

**References**:**Calculating derivate in Mathematica 9 giving wrong result***From:*James <jhlawley@gmail.com>