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Invertiable for all values of theta

  1. Oct 20, 2012 #1
    Hi all,

    How do you go about solving this question as it says:

    Show that the matrix:

    | costheta sintheta 0 |
    B= | -sintheta costheta 0 |
    | 0 0 1 |

    is invertible for all values of theta [Hint. Show that det(B) is not equal of all values of theta ]


  2. jcsd
  3. Oct 20, 2012 #2


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    Hi Stephen! :smile:
    I don't get it :confused:

    everybody knows that the inverse of that is the same but with -θ instead of θ;

    and det(B) is always 1.
  4. Oct 20, 2012 #3


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    You are given a hint. Did it not occur to you to do what the hint said? What is the determinant of that matrix?
  5. Oct 20, 2012 #4


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    Is that a typo?
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