[Date Index] [Thread Index] [Author Index]

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