http://www.mapleprimes.com/posts/38233-Implicit-Differentiation-With-The-Chain-Rule en-us 2026 Maplesoft, A Division of Waterloo Maple Inc. Maplesoft Document System Thu, 11 Jun 2026 13:46:50 GMT Thu, 11 Jun 2026 13:46:50 GMT The latest comments added to the Post, implicit differentiation with the chain rule http://www.mapleprimes.com/images/mapleprimeswhite.jpg http://www.mapleprimes.com/posts/38233-Implicit-Differentiation-With-The-Chain-Rule http://www.mapleprimes.com/posts/38233-Implicit-Differentiation-With-The-Chain-Rule?ref=Feed:MaplePrimes:implicit differentiation with the chain rule:Comments#comment68513 <pre> &gt; convert(simplify(diff(sqrt(u(x)^2),x)),abs) assuming u(x)::real; /d \ u(x) |-- u(x)| \dx / -------------- | u(x) | &gt; PDEtools:-declare(u(x)); u(x) will now be displayed as u &gt; convert(simplify(diff(sqrt(u(x)^2),x)),abs) assuming u(x)::real; u u[x] ------ | u | </pre> <p>acer</p> The latest comments added to the Post, implicit differentiation with the chain rule 68513 Mon, 08 Dec 2008 21:26:11 Z acer acer http://www.mapleprimes.com/posts/38233-Implicit-Differentiation-With-The-Chain-Rule?ref=Feed:MaplePrimes:implicit differentiation with the chain rule:Comments#comment68389 <p>Sorry to take so long to continue this thread.&nbsp; The first command is OK but the second</p> <p>&nbsp;&nbsp;&nbsp;&nbsp; PDEtools:-declare(u(x));</p> <p>gives the error message</p> <p>&nbsp;&nbsp;&nbsp;&nbsp; 'PDEtools' does not evaluate to a module.</p> <p>How to fix this?</p> <p>Alla</p> The latest comments added to the Post, implicit differentiation with the chain rule 68389 Wed, 17 Dec 2008 00:19:56 Z alla alla http://www.mapleprimes.com/posts/38233-Implicit-Differentiation-With-The-Chain-Rule?ref=Feed:MaplePrimes:implicit differentiation with the chain rule:Comments#comment82407 <p>I guess you're using an earlier version of Maple: in Maple 12 it would work, but in some earlier versions PDEtools is still a table-based package.&nbsp; So:</p> <pre> &gt; PDEtools[declare](u(x)); </pre> <p>&nbsp;</p> <p>&nbsp; </p> The latest comments added to the Post, implicit differentiation with the chain rule 82407 Wed, 17 Dec 2008 00:49:49 Z Robert Israel Robert Israel