Verify that M(theta) is orthogonal, and find a unit vectornsuch that the line fixed by the reflection is given by the equation

n . x =c,

for a suitable constant c, which should also be determined.

---------------

I did the verficiation part, by multiplying m(theta) by its transpose. But how do I do the 2nd part? (regarding the find a unit vector).

http://img268.imageshack.us/img268/4686/123wrm.jpg