TITLE: Is there any way to represent an imaginary number?
QUESTION [8 upvotes]: Is there any way to represent an imaginary number? Like the square root of -1? Is there any possible way to do this?
Sorry if you think this is a dumb question. I am a 7th grade student in trigonometry. And I just wanted to ask.

REPLY [2 votes]: I'll add my two cents. 
The study of imaginary, and complex, numbers is arguably one of the most beautiful parts of mathematics. If you follow this path, you will learn that complex numbers turn out to be extremely useful in almost all parts of mathematics. What could the square root of $-1$ possibly have in common with the notion of prime numbers? It looks like a strange idea at first. Yet, it turns out that the most interesting unproven hypotheses about prime numbers can be expressed in terms of complex numbers. GEdgar said that electrical engineers use complex numbers. What about chemists, cryptographers, physicists, etc? It's astonishing how fantastically useful this superficially artificial notion is.