Similarly, if we look at time t is equal to zero, we know what we should have.

It should be V sub s, R3 divided by R1 plus R2 plus R3.

And the reason is because the capacitor

has a property in which the voltage cannot change across it instantaneously.

So at t is equal to 0 minus,

this is a voltage at t is equal to 0 plus, this is a voltage.

So if we go over here, and we look at our equation, we evaluate it for

t is equal to 0, this term goes to 1, the exponential does,

and what that leaves us with is these three terms and

we look at that we would end up with this as our Vc

at t is equal to 0 and that's correct because it's the same as what we have for

Vc for t is equal to 0 minus.

So this indeed is a correct, complete response for

the capacitor voltage as a function of time for t greater than or equal to zero.