Understanding Eigenvalues and Eigenvectors in Reflection Matrices

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Homework Statement



Let A be a matrix corresponding to reflection in 2 dimensions across the line generated by a vector v . Check all true statements:

A. lambda =1 is an eigenvalue for A
B. Any vector w perpendicular to v is an eigenvector for A corresponding to the eigenvalue lambda =1.
C. The vector v is an eigenvector for A corresponding to the eigenvalue lambda =1.
D. Any vector w perpendicular to v is an eigenvector for A corresponding to the eigenvalue lambda =−1.
E. lambda =−1 is an eigenvalue for A
F. None of the above

The Attempt at a Solution



I honestly have no clue how to do this question. Can somebody explain to me what the question is asking and how to solve it?
 
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Do you know what the definition of an eigenvalue/eigenvector is? Think about the case where A just reflects over the x-axis first in R2 in order to get a handle on what the question is asking
 
There are two things I don't understand about this problem. First, when finding the nth root of a number, there should in theory be n solutions. However, the formula produces n+1 roots. Here is how. The first root is simply ##\left(r\right)^{\left(\frac{1}{n}\right)}##. Then you multiply this first root by n additional expressions given by the formula, as you go through k=0,1,...n-1. So you end up with n+1 roots, which cannot be correct. Let me illustrate what I mean. For this...
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