Imaginary unit - electrical charge relationship

Helicobacter

In my Algebra 2 textbook it says that the imaginary unit finds practical application in electrical engineering. Is that because the imaginary unit is as elusive as electrical charge to rational perception?

Hurkyl

We use the real numbers for tasks well suited to using real numbers -- not because they're more "real' than other sorts of numbers.

In particular, real numbers have an ordering, so they are useful for describing things that have an ordering. In particular, they're good for describing magnitudes.


Similarly, we use complex numbers for tasks well suited to using complex numbers. For example, complex numbers can be viewed has having a magnitude and a phase (whereas the real numbers can only muster a magnitude and a sign). Thus, complex numbers are better than real numbers for describing things that have a phase. (For example, waves)

berkeman

Good comments by Hurkyl. In addition, here are some more comments about complex numbers and complex math in engineering and physics from a recent thread.

http://www.physicsforums.com/showthread.php?t=109715