# Laplace of the differential of another variable in sage

Why did the diff(y.laplace(t,s),x) come out to be `D[0](laplace)(y(x, t), t, s)*D[0](y)(x, t)`

? Could someone help me?

Laplace of the differential of another variable in sage

`D[0](laplace)(y(x, t), t, s)*D[0](y)(x, t)`

? Could someone help me?

add a comment

1

As best I can tell, it looks like Sage is doing the chain rule here. So, it is treating `laplace(y,t,s)`

as a symbol and gives the derivative w.r.t. x as `D[0](laplace(y,t,s))*D[0](y(x,t))`

. Taking the second derivative gives something that looks like the product rule and the chain rule were used.

I think Sage is using Maxima to do this. So, this might be an issue with how Maxima handles partial derivatives of Laplace transforms.

Asked: **
2012-08-20 22:47:19 -0500
**

Seen: **139 times**

Last updated: **Sep 10 '12**

Copyright Sage, 2010. Some rights reserved under creative commons license. Content on this site is licensed under a Creative Commons Attribution Share Alike 3.0 license.