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There are three definitions we discussed in class for linearity.  
 
There are three definitions we discussed in class for linearity.  
  
<u></u><u>Definition 1</u>  
+
<u></u>'''<u>Definition 1</u>'''
  
<u></u>A system is called '''linear''' if for any constants <math>a,b\in </math>&nbsp; ''all complex numbers'' and for any input signals <span class="texhtml">''x''<sub>1</sub>(''t''),''x''<sub>2</sub>(''t'')</span> with response <span class="texhtml">''y''<sub>1</sub>(''t''),''y''<sub>2</sub>(''t'')</span>, respectively, the system's response to <span class="texhtml">''a''''x'''''<b><sub>1</sub>(''t'') + ''b'''''x''<sub>2</sub>(''t'')'''''&lt;/span&gt;'''''is &lt;span class="texhtml" /&gt;''a''''y'''''&lt;b&gt;<sub>1</sub>('''''t'') + ''b''''''''y''<sub>2</sub>(''t''). '''
+
<u></u>A system is called '''linear''' if for any constants <math>a,b\in </math>&nbsp; ''all complex numbers'' and for any input signals <span class="texhtml">''x''<sub>1</sub>(''t''),''x''<sub>2</sub>(''t'')</span> with response <span class="texhtml">''y''<sub>1</sub>(''t''),''y''<sub>2</sub>(''t'')</span>, respectively, the system's response to <span class="texhtml">''ax''<sub>1</sub>(''t'') + ''b''x''<sub>2</sub>(''t'')''&nbsp;''is ''ay''<sub>1</sub>(''t'') + ''b''y''<sub>2</sub>(''t'').&nbsp;</span>
</span>
+
  
 +
'''
 
<u>Definition 2</u>  
 
<u>Definition 2</u>  
  
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<math> ax_1(t) + bx_2(t) \rightarrow \begin{bmatrix} system \end{bmatrix} \rightarrow ay_1(t) + by_2(t) </math>  
 
<math> ax_1(t) + bx_2(t) \rightarrow \begin{bmatrix} system \end{bmatrix} \rightarrow ay_1(t) + by_2(t) </math>  
  
for any <math>a,b\in </math>&nbsp; ''all complex numbers'', any <span class="texhtml">''x''<sub>1</sub>(''t''),''x''<sub>2</sub>(''t'')</span> then we say the system is '''linear'''.  
+
<span class="Apple-style-span" style="font-weight: normal;">for any <math>a,b\in </math>&nbsp; </span>''<span class="Apple-style-span" style="font-weight: normal;">all complex numbers</span>''<span class="Apple-style-span" style="font-weight: normal;">, any </span><span class="texhtml">''<span class="Apple-style-span" style="font-weight: normal;">x</span>''<sub><span class="Apple-style-span" style="font-weight: normal;">1</span></sub><span class="Apple-style-span" style="font-weight: normal;">(</span>''<span class="Apple-style-span" style="font-weight: normal;">t</span>''<span class="Apple-style-span" style="font-weight: normal;">),</span>''<span class="Apple-style-span" style="font-weight: normal;">x</span>''<sub><span class="Apple-style-span" style="font-weight: normal;">2</span></sub><span class="Apple-style-span" style="font-weight: normal;">(</span>''<span class="Apple-style-span" style="font-weight: normal;">t</span>''<span class="Apple-style-span" style="font-weight: normal;">)</span></span><span class="Apple-style-span" style="font-weight: normal;"> then we say the system is</span> '''linear'''.  
  
 
<u>Definition 3</u>
 
<u>Definition 3</u>
 +
'''
  
<u></u>A system is '''linear '''
+
<u></u>A system is''''''linear''''''

Revision as of 07:26, 6 May 2011

Linearity

There are three definitions we discussed in class for linearity.

Definition 1

A system is called linear if for any constants $ a,b\in $  all complex numbers and for any input signals x1(t),x2(t) with response y1(t),y2(t), respectively, the system's response to ax1(t) + bx2(t) is ay1(t) + by2(t). 

Definition 2

If

$ x_1(t) \rightarrow \begin{bmatrix} system \end{bmatrix} \rightarrow y_1(t) $

$ x_2(t) \rightarrow \begin{bmatrix} system \end{bmatrix} \rightarrow y_2(t) $

then

$ ax_1(t) + bx_2(t) \rightarrow \begin{bmatrix} system \end{bmatrix} \rightarrow ay_1(t) + by_2(t) $

for any $ a,b\in $  all complex numbers, any x1(t),x2(t) then we say the system is linear.

Definition 3

A system is'linear'

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