# Clarification of PDE.

• February 10th 2010, 03:21 PM
yungman
Clarification of PDE.
What is the meaning of $\;\;\frac{\partial u}{\partial t}(x,0)$

Is it equal to $\;\;\frac{\partial u(x,t)}{\partial t}\;\;then\;set\;x=0$

or $\;\;\;\frac{\partial u(x,0)}{\partial t}$
• February 10th 2010, 03:32 PM
Jester
Quote:

Originally Posted by yungman
What is the meaning of $\;\;\frac{\partial u}{\partial t}(x,0)$

Is it equal to $\;\;\frac{\partial u(x,t)}{\partial t}\;\;then\;set\;x=0$

or $\;\;\;\frac{\partial u(x,0)}{\partial t}$

It means the first. You can't calculate

$\;\;\;\frac{\partial}{\partial t}\left( u(x,0) \right).$
• February 10th 2010, 03:35 PM
yungman
Thanks (Happy)