Math Is Fun Forum
You are not logged in.
- Topics: Active | Unanswered
#1 2006-09-18 10:05:58
- Ultima Black Gate
- Member
- Registered: 2006-09-18
- Posts: 14
Complex Numbers, know what they are but not what are they for.
What are complex numbers for anyway?
I know they are (a + bi) where a and b are real numbers and i is imaginary (-1 square root) and i know how to do basic operations with them but what are they used for?
Im a newbie with this, and the concept is very weird for me, not regarding HOW but regarding WHY studying complex numbers.
Basically any interesting info that you guys could share with me will be apreciated.
.
Last edited by Ultima Black Gate (2006-09-18 10:07:44)
Offline
#2 2006-09-18 11:00:38
- Dross
- Member
- Registered: 2006-08-24
- Posts: 325
Re: Complex Numbers, know what they are but not what are they for.
Probably the first actual use you'd encounter for complex numbers (on a "standard" maths course) will be in solving differential equations. Essentially what you do when solving some types of differential equation involves making them into complex numbers and processing them, and you'll get a real answer at the end. (More specifically, you sometimes have to find all the roots of a given quadratic equation - even if they are complex - and use them to get a solution) Complex numbers have a fair amount of these applications where they're part of the inner workings of a system without being a part of the output or the input.
A major direct use for complex numbers is in quantum physics, as things according to quantum theory are defined over the complex plane, as opposed to the real line. If you have a search on the web for the Schrodinger or Heisenberg equations, they explicitly use the imaginary unit, i.
Bad speling makes me [sic]
Offline
#3 2006-09-18 12:14:58
- MathsIsFun
- Administrator
- Registered: 2005-01-21
- Posts: 7,713
Re: Complex Numbers, know what they are but not what are they for.
Also electronics - alternating current. Resistors and capacitors behave differently with AC than with DC. The math would get horrendous if you had to plot the behaviour over time. But reducing it to complex numbers makes it a lot easier.
"The physicists defer only to mathematicians, and the mathematicians defer only to God ..." - Leon M. Lederman
Offline