(New page: == Operations with Complex Numbers == Complex numbers can be added, subtracted, multiplied, and divided from each other using simple mathematical properties, namely the associative, commu...)
 
 
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== Operations with Complex Numbers ==
 
== Operations with Complex Numbers ==
  
Complex numbers can be added, subtracted, multiplied, and divided from each other using simple mathematical properties, namely the associative, commutative, and distributive ones.  It is also important to remember that
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Complex numbers can be added, subtracted, multiplied, and divided from each other using simple mathematical properties, namely the associative, commutative, and distributive ones.  It is also important to remember that <math> j^2 = -1 </math>. 
  
</math> i^2 = -1 </math>
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=== Some Examples: ===
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==== Addition/Subtraction ====
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<math> \,\! (a + b*j) + (c + d*j) = (a + c) + (b + d)*j </math>
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<math> \,\! (a + b*j) - (c + d*j) = (a - c) + (b - d)*j </math>
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==== Multiplication/Division ====
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Multiplication and division are a little more complicated than addition and subtraction, mostly because when <math> j </math> is multiplied by itself, it results in a <math> -1 </math>.
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<math> \,\! (a + b*j)*(c + d*j) = a*c + a*d*j + b*c*j + b*d*j^2 </math><br>
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<math> \,\!                    = a*c + (a*d + b*c)*j + (-1)*b*d </math><br>
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<math> \,\!                    = (a*c - b*d) + (a*d + b*c)j </math><br>
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When dividing, it is important to know that <math> j </math> should never be in the denominator
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<math> \,\! \frac{(a + b*j)}{(c + d*j)} = \frac{(a*c + b*d)}{(c^2 + d^2)} + \frac{(b*c - a*d)}{(c^2 + d^2)}*j

Latest revision as of 15:42, 3 September 2008

Operations with Complex Numbers

Complex numbers can be added, subtracted, multiplied, and divided from each other using simple mathematical properties, namely the associative, commutative, and distributive ones. It is also important to remember that $ j^2 = -1 $.

Some Examples:

Addition/Subtraction

$ \,\! (a + b*j) + (c + d*j) = (a + c) + (b + d)*j $

$ \,\! (a + b*j) - (c + d*j) = (a - c) + (b - d)*j $


Multiplication/Division

Multiplication and division are a little more complicated than addition and subtraction, mostly because when $ j $ is multiplied by itself, it results in a $ -1 $.

$ \,\! (a + b*j)*(c + d*j) = a*c + a*d*j + b*c*j + b*d*j^2 $
$ \,\! = a*c + (a*d + b*c)*j + (-1)*b*d $
$ \,\! = (a*c - b*d) + (a*d + b*c)j $

When dividing, it is important to know that $ j $ should never be in the denominator

$ \,\! \frac{(a + b*j)}{(c + d*j)} = \frac{(a*c + b*d)}{(c^2 + d^2)} + \frac{(b*c - a*d)}{(c^2 + d^2)}*j $

Alumni Liaison

has a message for current ECE438 students.

Sean Hu, ECE PhD 2009