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== Definition ==
 
== Definition ==
  
  A complex number is made up of two parts, a real part and an imaginary part. An example is <math>a+bi</math>, where <math>a</math> is the real part and <math>b</math> is the imaginary part.
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<font size="3">A complex number is made up of two parts, a real part and an imaginary part. An example is
 +
 
 +
<math>a+bi</math>, where <math>a</math> is the real part and <math>b</math> is the imaginary part.</font>
  
 
== Addition ==
 
== Addition ==
  
 
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<font size="3"><math>(a + bj) + (c + dj) = (a + c) + (b + d)j</math></font>
  
 
== Subtraction ==
 
== Subtraction ==
  
 
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<font size="3"><math>(a + bj) - (c + dj) = (a - c) + (b - d)j</math></font>
  
 
== Multiplication ==
 
== Multiplication ==
  
 
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<font size="3"><math>(a + bj)(c + dj) = (ac - bd) + (ad + bc)j</math></font>
  
 
== Division ==
 
== Division ==
  
 
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<math>\frac{(a + bj)}{(c + dj)} = \frac{(a + bj)(c - dj)}{(c + dj)(c - dj)} =
 +
\frac{(a + bj)(c - dj)}{(c^2 - d^2)} = \frac{(ac + bd) + (bc - ad)j}{(c^2 - d^2)}</math>
  
 
== Applications ==
 
== Applications ==
 +
<font size="3">Applications include:
 +
 +
- Control Theory
 +
 +
- Fluid Flow
 +
 +
- Signal Processing
 +
 +
- Quantum Mechanics
 +
 +
- Relativity
  
  Applications include:
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- Fractals (my personal favorite)</font>
    * Control Theory
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    * Fluid Flow
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    * Signal Processing
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    * Quantum Mechanics
+
    * Relativity
+
    * Fractals (my personal favorite)
+
  
 
== Sources ==
 
== Sources ==
  
 
http://en.wikipedia.org/wiki/Complex_numbers
 
http://en.wikipedia.org/wiki/Complex_numbers

Latest revision as of 13:23, 4 September 2008

Definition

A complex number is made up of two parts, a real part and an imaginary part. An example is

$ a+bi $, where $ a $ is the real part and $ b $ is the imaginary part.

Addition

$ (a + bj) + (c + dj) = (a + c) + (b + d)j $

Subtraction

$ (a + bj) - (c + dj) = (a - c) + (b - d)j $

Multiplication

$ (a + bj)(c + dj) = (ac - bd) + (ad + bc)j $

Division

$ \frac{(a + bj)}{(c + dj)} = \frac{(a + bj)(c - dj)}{(c + dj)(c - dj)} = \frac{(a + bj)(c - dj)}{(c^2 - d^2)} = \frac{(ac + bd) + (bc - ad)j}{(c^2 - d^2)} $

Applications

Applications include:

- Control Theory

- Fluid Flow

- Signal Processing

- Quantum Mechanics

- Relativity

- Fractals (my personal favorite)

Sources

http://en.wikipedia.org/wiki/Complex_numbers

Alumni Liaison

Recent Math PhD now doing a post-doctorate at UC Riverside.

Kuei-Nuan Lin