Why is the rank of n-dimensional unit column vector 1?

Why is the rank of n-dimensional unit column vector 1?


Matrix of n-dimensional unit column vector belonging to NX1
Rank of matrix = row rank = column rank
The rank of the column is 1, so the rank of the matrix is 1



When an n-dimensional vector is added to a group of n-dimensional vectors with rank n, the rank of the vector group is equal to?


n



Let a be a matrix of order n, α 1, α 2 and α 3 be n-dimensional nonzero vectors. If a α I = I α I (I = 1,2,3), it is proved that α 1, α 2 and α 3 are linearly independent


α 1, α 2 and α 3 are the eigenvectors corresponding to the eigenvalues 1, 2 and 3 of a respectively, so they are linearly independent



a. B is a three-dimensional column vector, matrix A = bat (b times (transpose of a)), what is the rank of matrix A? Why? If it is extended to n-dimension?


The rank of matrix A is less than or equal to 1
Because R (a) = R (BA ^ t)