1. The problem statement, all variables and given/known data Question is attached below 2. Relevant equations v(t) =v(infinity) + [v(t0)-v(infinity)]e^[-(t-t0)] 3. The attempt at a solution For t<0, you get the circuit where it is only Rt, R, and C, but in dc circuits, the capacitor is an open circuit, does this mean v(t0) =0? For t>0 the middle Rt is removed and you get a circuit consisting of Vt, Rt, R and C. To find Rth, you short circuit Vt and open circuit C, so Req= Rt+R. So time constant is C(Rt+R). To find v(infinity), we open circuit the the capacitator, but how do you solve for v(infinity)?