hello everybody,
this is a question that has been buffeling me for a while. everything is in this image: http://img398.imageshack.us/img398/5213/58136160lu9.jpg
i know 2 things:
1. the total (vector) flux is 0 (no charge inside the cube)
2. the flux through each side is \int_{S}*E dA
so I've...