What is the Significance of ∂Ω in Partial Differential Equations?

[Gregg]

http://ocw.mit.edu/courses/mathemat...quations-fall-2005/lecture-notes/lecture1.pdf

$$\int_{\partial \Omega} \nabla (v-u) \nabla (v+u).dS=...$$

What is [itex]\partial \Omega \text{?}[/tex][/itex]

 

[quasar987]

Apparently, $\Omega$ is a volume of space and $\partial \Omega$ denote its boundary. For instance, if $\Omega$ is the unit ball, then $\partial \Omega$ is the unit sphere.

 

[Gregg]

Ah thanks