how could you calculate the input voltage at an input impedance from a voltage source? I saw they use voltage division law to find the voltage at the input impedance(Zin) from a voltage source(Vs). They do it like Vs * Zin/(Zin+Zs). The problem came... We all know that we can determine the voltage only after considering all resistances in a circuit. They still have the transmission line and load impedance. If I denote them as Zt and Zl, wouldn't the voltage to the input impedance be Vs * Zin/(Zin+Zs+Zt+Zl) instead? Because if you simply consider Vs * Zin/(Zin+Zs), the voltage wave will be zero after going through the input impedance before even entering the transmission line connected with a load on the other end. This doesn't make any sense. Help.. If you don't understand what I am saying, please let me know.