What Does x' Represent in Electric Field Equations?

[charlotty]

now, i have absolutely no idea what the heck that means, and doubt i ever will, but my boyfriend is doing a dgree in electronic engineering and is studying fields and devices at the moment and is really stuck so i was wondering if anyone could help!

His notes say "the total e field is the vector sum over all the N charges. If we line up our axes so that the charges are on the x-axis then we get..."
a really long equation. (i would write it here, but there's no way to get all the equations symbols!)

THe equation has a x' in it, and he has no idea what the notation means.

im probably not making any sense to anyone, but i just wanted to see if i could help him (im studying for a law degree so this is all spanish to me!)

thanks so much,

charlotty

 

[marcusl]

Often a primed variable is used to indicate the position of a source while an unprimed variable is the observation point. Why not have your boyfriend post his question here?