Please assist with the following quesiton.
1. Consider two column vectors X,Z E Rn of equal length, e.g.< X,X >=< Z,Z >. Define the following matrix
2
U=:I- -(X- Z)(X - Z)T <X-Z,X-Z>
Prove that UUT = UTU = I and UX = Z.
How such orthogonal matrices are called, why( and in what applica- tions) are they useful/cool?