(Complex Numbers)
(Complex Numbers)
Line 22: Line 22:
 
'''Euler's Formula: <math>e^{jt} = cos(t) + j*sin(t)</math>'''
 
'''Euler's Formula: <math>e^{jt} = cos(t) + j*sin(t)</math>'''
  
Q1.  What are the real and imaginary parts of <math>e^{3jt}</math>?
+
Q1.  What are the real and imaginary parts of <math>e^{2*pi*jt}</math>?
 +
Q2.  Convert

Revision as of 19:05, 4 September 2008

Complex Numbers

Complex numbers are very important for mathmeticians and engineers alike. However, the two use slightly different terminologies. Mathmeticians use "i" to denote an imaginary number, but electrical engineers use "j" to symbolize an imaginary number since "i" is used for current (specifically electron current since its a lower case "i").

As denoted below, "j" represents a -1 inside of a square-root. All complex numbers can be broken down into both a real part and an imaginary part. These two parts are best explained using graphical representation. The x-axis is the real part of the number. The y-axis represents the imaginary axis.

IMAGINARY  
    |      .
    |     /.
    |    / .
    |   /  .
    |  /   .
    | /    .
 ___|/_____.__REAL
    |
    |

Imaginary Number $ \Rightarrow j =sqrt(-1) $

Euler's Formula: $ e^{jt} = cos(t) + j*sin(t) $

Q1. What are the real and imaginary parts of $ e^{2*pi*jt} $? Q2. Convert

Alumni Liaison

Correspondence Chess Grandmaster and Purdue Alumni

Prof. Dan Fleetwood