So if we look at the circuit in this state,

it becomes fairly easy to decide what Vc at t is equals 0 minus is.

We know we can use voltage division to find Vc at t is equals to 0 minus.

It's simply going to be the amount of the source voltage which is dropped across

the R3 resistor at the right hand side of our circuit.

So Vc at t is equal to 0 minus is going to

be V sub s times R3 divided by R1 plus R2 plus R3.

Now lets look at the condition where t is equals to infinity to

get our other value, that is Vc of t at t is equals to infinity.

We're going to draw our circuit one more time.

And this time for the condition or the switch has been thrown and

creates a short circuit Around our resistor R1.

We still have resistors R2 and R3 in the circuit and

we still have our capacitor as well.

So we're going to draw those in.