repost - expanding inline d[xy]/dx during implicit differentiation

*To*: mathgroup at smc.vnet.net*Subject*: [mg113146] repost - expanding inline d[xy]/dx during implicit differentiation*From*: John Accardi <accardi at accardi.com>*Date*: Fri, 15 Oct 2010 13:51:26 -0400 (EDT)

Thanks in advance for any help ..... Implicit Differentiation Below, I need to get the inline d[xy]/dx to expand in the Dt output. Ditto for the output of Solve. (I have done other implicit differentiation calculations that have done this correctly.) What is the issue here? eq5=x^3-3x^2 y+2xy^2==12 x^3-3 x^2 y+2 xy^2\[LongEqual]12 Dt[eq5,x] -3 x^2 \[DifferentialD]y/\[DifferentialD]x+3 x^2+4 xy \[DifferentialD]xy/\[DifferentialD]x-6 x y\[LongEqual]0 Solve[%%,\[DifferentialD]y/\[DifferentialD]x] {{\[DifferentialD]y/\[DifferentialD]x->(3 x^2+4 xy \[DifferentialD]xy/\[DifferentialD]x-6 x y)/(3 x^2)}} *.nb is located here: http://www.accardi.com/ImplicitDifferentiationForumQueryTest.nb Thanks, Gianni