Imaginary numbers are square roots of negative real numbers that were introduced to allow taking the square root of negatives. An example of an imaginary number is 2i√6, where i represents the imaginary unit. Imaginary numbers can be added, subtracted, multiplied, and divided like real numbers. When squared, imaginary numbers follow a repeating sequence of i, -1, -i, 1. Though sometimes complex, imaginary numbers serve an important purpose and are generally easy to work with through practice.