#### jmvalks

##### Newbie level 5

The problem goes like this:

A capacitance of C farads has a current i = (V

_{m}/R)e

^{-(t/RC)}(A). Show that the maximum stored energy is (1/2)CV

_{m}

^{2}.

I have taken the basic equation i = Cdv/dt and integrated to get v. Then I multiply the two to get power. Unfortunately this looks as if it is not going anywhere so I have not attempted to take the time integral of this to get energy.

The only assumption I can make is that the maximum energy will be stored at t = infinity, i.e. when it is fully charged.

The equation suggests a resistor in series but no hint of this is given in the question so I have not assumed there is one. I have worked solely from the facts given along with my assumption above.

Have I tackled this the wrong way? I don't mind working through the math if someone can point me in the right direction.

Thanks for any help with this one.