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Math Help - what is n_2?

  1. #1
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    what is n_2?

    in one of my questions a 2x2 matrix is mentioned that is  \eta_{2}, it doesnt tell me what it is but somewhere else in my notes it mentions that det(\eta_{2})=-1. can someone please tell me (quickly) what this matrix is?
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  2. #2
    MHF Contributor Drexel28's Avatar
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    Re: what is n_2?

    Quote Originally Posted by wik_chick88 View Post
    in one of my questions a 2x2 matrix is mentioned that is  \eta_{2}, it doesnt tell me what it is but somewhere else in my notes it mentions that det(\eta_{2})=-1. can someone please tell me (quickly) what this matrix is?
    Haha, there are quite a few matrices with \det(\eta_2)=-1. Can you give us more context.
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  3. #3
    MHF Contributor FernandoRevilla's Avatar
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    Re: what is n_2?

    In general, a linear transformation with negative determinant changes orientation, but as Drexel28 comments, we need more context. For example if A\in\mathbb{R}^{2\times 2} with \det A=-1 and A orthogonal we have a symmetry with respect to a line.
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