Hi, my name is Bassem Saad. I'm a Math Ph.D. candidate at U.C. Davis, and I'm here today for About.com to show you how to solve functions involving i.Remember, i squared equals negative one; or, equivalently, negative i times i equals one. Allowing this imaginary number to exist gives solutions to old problems. For example, say we had x squared plus one equals zero. We can solve for x by subtracting one from both sides to give us x squared equals negative one. Then we take the square root to give us plus/minus the square root of negative one; but the square root of negative one is just i. So now we have our solution to this polynomial.i can also come up as a coefficient in an equation. We can use the properties of i to still find solutions to the equation. For example: i times x minus five equals one. We can still solve for x. First thing we want to do is get everything that's not times x to one side of the equation. So we can add five to both sides to get i times x equals six. The next thing we want to do is get rid of this i. But, remember, negative i times i equals one. So if we multiply negative i times both sides – so negative i, times negative i – we get our solution, which is just x equals negative six i.Every electrical engineer must be able to solve equations involving i. This skill is crucial for physicists, engineers, and scientists of all types.Thanks for watching, and to learn more, visit us on the web at About.com.