A computational problem in Electromagnetics

Two point charges are charged at 2q and Q, apart from L, where the third point charge is placed where the resultant force is zero?

Download the answer on the internet said that if Q and 2q also have Q same number, then the three mutual exclusion can not achieve balance, so Q must and 2q and q different

I think the problem of symbols does not affect the result, in fact I think that the answer to the question of the understanding may be wrong

Since 2q and q are the same number, if q is between the lines of 2q and Q, the two Coulomb forces that are subjected must be in the opposite direction.

So you can directly solve

A computational problem in Electromagnetics