(Example)
(Example)
 
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==Example==
 
==Example==
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'''Linear'''
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Given:
 
Given:
  
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a*x1(t)+b*x2(t)=at+5bt-> system ->Output=2*(at+2bt)= 2at + 10bt  <-- answer B
 
a*x1(t)+b*x2(t)=at+5bt-> system ->Output=2*(at+2bt)= 2at + 10bt  <-- answer B
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answer A = answer B, proves that it's a linear system
 
answer A = answer B, proves that it's a linear system
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 +
'''Non Linear'''
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 +
Given:
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 +
x1(t)=t, x2(t)=5t
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 +
System: y(t)=x(t)^2
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 +
Thus, y1(t)=t^2,y2(t)=(5t)^2<br>
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So say a,b are any non-zero constant<br>
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a*x1(t)-> system ->(at)^2<br>
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b*x2(t)-> system ->(5bt)^2<br>
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Therefore, the output is (at)^2 + (5bt)^2 <-- answer A
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 +
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a*x1(t)+b*x2(t)=at+5bt-> system ->Output=(at+25t)^2  <-- answer B
 +
 +
answer A != answer B, proves that it's a non linear system

Latest revision as of 17:46, 12 September 2008

What Is a Linear System

A linear system has to satisfy these contions:
If the inputs x1(t),x2(t),(x1[n],x2[n]) multiplied/divided by any constant a,b, then the output y1(t),y2(t),(y1[n],y2[n]) will yield a*x1(t)+b*x2(t) --> a*y1(t)+b*y2(t) and respectively

Example

Linear

Given:

x1(t)=t, x2(t)=5

System: y(t)=2*x(t)

Thus, y1(t)=2t,y2(t)=10t
So say a,b are any non-zero constant
a*x1(t)-> system ->2at
b*x2(t)-> system ->10bt
Therefore, the output is 2at + 10bt <-- answer A


a*x1(t)+b*x2(t)=at+5bt-> system ->Output=2*(at+2bt)= 2at + 10bt <-- answer B

answer A = answer B, proves that it's a linear system

Non Linear

Given:

x1(t)=t, x2(t)=5t

System: y(t)=x(t)^2

Thus, y1(t)=t^2,y2(t)=(5t)^2
So say a,b are any non-zero constant
a*x1(t)-> system ->(at)^2
b*x2(t)-> system ->(5bt)^2
Therefore, the output is (at)^2 + (5bt)^2 <-- answer A


a*x1(t)+b*x2(t)=at+5bt-> system ->Output=(at+25t)^2 <-- answer B

answer A != answer B, proves that it's a non linear system

Alumni Liaison

has a message for current ECE438 students.

Sean Hu, ECE PhD 2009