Understanding the Imaginary Unit i

i is the imaginary unit, defined by the rule “i squared equals minus one.” It lets

us take square roots of negative numbers that real numbers can’t handle. For example,

the equation “x squared plus one equals zero” has solutions “x equals plus or minus i.”

Even though it’s called imaginary, it’s very useful in algebra, engineering,

circuits, waves, computing, and many areas of advanced math.