The time constant in the solution is 0.5. (-2t implies tau = 0.5) I am wondering how they got this.
tau = RC
So I am wondering how to calculate the Rth. The capacitor is inbetween the two resistors in series, so would the Rth be
Rth = 6/(6+2)
But then tau = (6/8)*(1/3) = 0.25
if Rth is not calculated like this and is just = (6+2)
tau = 8*(1/3) which is not equal to 0.5
if Rth is also not calculated like this and is 2/(6+2)
tau = (2/8)*(1/3) which is not equal to 0.5
I know that I can get the Rth from the solution ie. since the solution says tau = 0.5, then the Rth must be 1.5ohms (since 1.5 * (1/3) = 0.5)
But I cannot see how the resistance at the terminals of the resistor is equivalent to 1.5ohms.
So my question is how to calculate Rth and how to calculate tau.