I need to resolve this network and find the equation for voltage at some time, t'>0. I know how to find the equation, but I'm having trouble finding the value for tau because I'm not sure what the equivalent resistance is.
tau = R*C
R1 = 4 k ohms
R2 = 7 k ohms
R3 = 2 k ohms
C = 101 microF
The Attempt at a Solution
I've tried resolving the resistors in different ways, but I can't seem to figure out how they combine to find R equivalent.
I'm just looking for a hint as to how the total resistance can be found when t > 0.