- #1

- 164

- 1

[itex]

\sigma_{b} = \vec{P}\bullet\hat{n}

[/itex]

Now, integrate both sides over a closed surface,

[itex]

\oint \sigma_{b} da = \oint (\vec{P}\bullet\hat{n}) da

[/itex]

My math is fuzzy, and I don't really understand this next step.

[itex]

\oint \sigma_{b} da = \oint \vec{P} \bullet d\vec{a}

[/itex]

What's going on here?

Thank you for your time!