My circuit looks similar to this:

When I calculate \(V_{TH}\) in this circuit, there is no current flowing through \(R_2\) so it is taken out of the equation. However when I calculate \(R_{TH}\) , I am supposed to use it in the equation.

I don't understand this. If there is no voltage drop across \(R_2\) and no current flowing through it, why is its existence even taken into account when calculating total resistance?

Thanks,

Winger