Denote the voltage in a circuit at time by . Let

Calculate the following:

- Average voltage over the interval .
- The root-mean-square of the voltage

- Denote the average of by and compute,
- The root-mean-square is given by the square root of the function over the interval . This gives us
Where we used the formula from the solution of Example 3, p. 101 of Apostol, to compute the integral .