# Formula relation to charge and time?

1. May 14, 2007

My circuit analysis professor put the following formula on the blackboard today:

$$Q(t_1) = \int_{t_0}^{t_1} idt +q(t_0)$$

What does this mean in relation to charge and time? He said that $$q(t_0)$$ is the initial charge.

Last edited: May 14, 2007
2. May 15, 2007

### Pyrrhus

Look it this way:

$$\frac{dQ}{dt} = i$$

$$\int_{t_{0}}^{t_{1}} dQ = \int_{t_{0}}^{t_{1}} idt$$

Then what follows is what your teacher wrote. Look at the first equation with the concept of derivative in mind...