1. The problem statement, all variables and given/known data hey guys. im new to the board. ive seen this problem on a website of which i'll list below. im not sure how came up with that formula for e. http://hyperphysics.phy-astr.gsu.edu/HBASE/electric/thevenin.html -> is the link to the page. i understand the rest of the problem, thaz teh only thing thaz giving me a hard time. thanks in advance for ur helps. cheers.