Math Help - Clarification of PDE.

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

2. 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

$\;\;\;\frac{\partial}{\partial t}\left( u(x,0) \right).$

3. Thanks