(Linearity)
(Linearity)
Line 9: Line 9:
 
  Let x1[n] = <math>2n</math>  
 
  Let x1[n] = <math>2n</math>  
 
     x2[n] = <math>n^2</math>
 
     x2[n] = <math>n^2</math>
 +
 +
x1[n] + x2[n] = xtot[n] = <math>2n + n^2</math> ===> ytot[n] = 4* xtot[n] = <math>8n + 4n^2</math>
  
x1[n] + x2[n] = xtot[n] = <math>2n + n^2</math> ===> ytot[n] = 4* xtot[n] = <math>8n + 4n^2</math>
+
x1[n] ==> y1[n] = 8n              x2[n] ==> y2[n] = <math>4n^2</math>
 +
 
 +
ytot = y1[n] + y2[n] = <math>8n + 4n^2</math>
 +
 
 +
<math>8n + 4n^2</math>  =    <math>8n + 4n^2</math>
 +
 
 +
Since the output of the two are the same, the system is linear.

Revision as of 09:01, 11 September 2008

Linearity

Linearity- A system is linear if a constant that multiplies an input to a system is also present in the output. Adding any number of linear combinations of complex numbers and functions of time together does not affect the linearity of the system.

A*x1(t) + B*x2(t) => A*y1(t) + B*y2(t) .... extendable for any amount of complex numbers (A, B, C...) and functions (x1, x2, x3...)

Linear System:  y[n] = 4 * x[n]
Let x1[n] = $ 2n $ 
    x2[n] = $ n^2 $

x1[n] + x2[n] = xtot[n] = $ 2n + n^2 $ ===> ytot[n] = 4* xtot[n] = $ 8n + 4n^2 $
x1[n] ==> y1[n] = 8n               x2[n] ==> y2[n] = $ 4n^2 $
ytot = y1[n] + y2[n] = $ 8n + 4n^2 $
$ 8n + 4n^2 $   =    $ 8n + 4n^2 $
Since the output of the two are the same, the system is linear.

Alumni Liaison

Abstract algebra continues the conceptual developments of linear algebra, on an even grander scale.

Dr. Paul Garrett