We finished More work with imaginary numbers today, in particular simplifying expressions that involve multiplying them or with higher powers. We saw in the videos we watched previously that powers of *i* don’t increase like other real numbers, but instead cycle through the numbers 1, *i*, -1, *-i*, and then back to 1 again.

We also discussed briefly how these new numbers work with allowing us to solve previously unsolvable quadratic equations, which we will reinforce tomorrow.

## Today’s Files

- Copy of Class Notes
- HW 4.11 – Multiplying Complex Numbers
- Lesson Video 1 (multiplying complex numbers)
- Lesson Video 2 (powers of
*i*) - Video Archive