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'''Tricks for checking Linear Independence, Span and Basis'''  
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'''<math>$M =
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\begin{array}{cc}
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x & y \\
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z & w \\
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\end{array}$</math>Tricks for checking Linear Independence, Span and Basis'''  
  
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<br>
  
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<br> <u>'''Linear Independence'''</u>
  
 
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If det(vectors)&nbsp;!= 0 ⇔ '''linearly independent'''<br> If end result of the rref(vectors) gives you a matrix with all rows having leading 1's it is '''linearly independent'''.  
<u>'''Linear Independence'''</u>
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If det(vectors)&nbsp;!= 0 ⇔ '''linearly independent'''<br> If end result of the rref(vectors) gives you a matrix with all rows having leading 1's it is '''linearly independent'''.
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If det(vectors) = 0 ⇔ '''linearly dependent'''<br>If end result of the rref(vectors) gives you a parameter in the equation, the vectors are '''linearly dependent.'''  
 
If det(vectors) = 0 ⇔ '''linearly dependent'''<br>If end result of the rref(vectors) gives you a parameter in the equation, the vectors are '''linearly dependent.'''  
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If Dimension &gt; #No of vectors -&gt; '''it CANNOT span'''  
 
If Dimension &gt; #No of vectors -&gt; '''it CANNOT span'''  
  
If det(vectors)&nbsp;!= 0 ⇔ it spans<br>If end result of the rref(vectors) gives you a matrix with all rows having leading 1's, '''it spans'''.
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If det(vectors)&nbsp;!= 0 ⇔ it spans<br>If end result of the rref(vectors) gives you a matrix with all rows having leading 1's, '''it spans'''.  
  
If det(vectors) = 0 ⇔ '''does not span'''<br>If end result of the rref(vectors) gives you a matrix with not all rows having a leading 1, it '''does not span.'''
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If det(vectors) = 0 ⇔ '''does not span'''<br>If end result of the rref(vectors) gives you a matrix with not all rows having a leading 1, it '''does not span.'''  
  
 
<u>'''Basis'''</u><br>  
 
<u>'''Basis'''</u><br>  
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If #No of vectors &gt; Dimension -&gt; it has to be linearly dependent to span (check the tip)  
 
If #No of vectors &gt; Dimension -&gt; it has to be linearly dependent to span (check the tip)  
  
If #No of vectors = Dimension -&gt; it has to be linearly independent to span<br>  
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If #No of vectors = Dimension -&gt; it has to be linearly independent to span<br> <span class="texhtml">''I''''n''''s''''e''''r''''t''''f''''o''''r''''m''''u''''l''''a''''h''''e''''r''''e''</span>  
  
 
[[Category:MA265Spring2011Momin]]
 
[[Category:MA265Spring2011Momin]]

Revision as of 08:20, 1 May 2011

$ $M = \begin{array}{cc} x & y \\ z & w \\ \end{array}$ $Tricks for checking Linear Independence, Span and Basis



Linear Independence

If det(vectors) != 0 ⇔ linearly independent
If end result of the rref(vectors) gives you a matrix with all rows having leading 1's it is linearly independent.

If det(vectors) = 0 ⇔ linearly dependent
If end result of the rref(vectors) gives you a parameter in the equation, the vectors are linearly dependent.

Tip: If #No of vectors > Dimension ⇔ it is linearly dependent

Span

If Dimension > #No of vectors -> it CANNOT span

If det(vectors) != 0 ⇔ it spans
If end result of the rref(vectors) gives you a matrix with all rows having leading 1's, it spans.

If det(vectors) = 0 ⇔ does not span
If end result of the rref(vectors) gives you a matrix with not all rows having a leading 1, it does not span.

Basis


If Dimension > #No of vectors ⇔ cannot span ⇔ is not a basis

If #No of vectors > Dimension -> it has to be linearly dependent to span (check the tip)

If #No of vectors = Dimension -> it has to be linearly independent to span
I'n's'e'r't'f'o'r'm'u'l'a'h'e'r'e

Alumni Liaison

Basic linear algebra uncovers and clarifies very important geometry and algebra.

Dr. Paul Garrett