What does n-dimensional vector mean

What does n-dimensional vector mean

N-dimensional vector with n coordinate components, i.e. vectors in n-dimensional space
For example, a plane is two-dimensional, equivalent to a two-dimensional vector
For example, a solid is three-dimensional, equivalent to a three-dimensional vector

What does the length of the n-dimensional column vector is 1 mean Given a is n-dimensional column vector and its length is 1, prove matrix H=E-2aa^T

The length of the n-dimensional column vector is 1, meaning a^Ta=1

When m > n, m n-dimensional vectors must be linear (, You'd better write down the process.

Related,
Let An×m=(α1,
α2,...,αM), then R (A)≤n.
Sublinear equations Ax=x1α1+x2α2+...+xmαm=0 have nonzero solutions.m
N-dimensional vector vectors α1,α2,...,αm must be linearly related.

A vector group consisting of m n-dimensional vectors must be linearly related when (). Fill in the blanks A vector group consisting of m n-dimensional vectors is linearly related when (). Fill in the blanks

M > n

M n-dimensional vectors (m > n), linear correlation? , Analyze from row and column vectors

Linear correlation.
If the number of vectors is larger than the dimension of the vector, the vector group is linearly related.
Row vector column vector one thing.

A is the vector of n-dimensional unit column, and A=E-aa^T is the rank of A

The characteristic value of known aa^T is 1,0,0,...,0
Therefore, the characteristic value of A=E-aa^T is 0,1,1,...,1
Since A is a real symmetric matrix, r (A) is equal to the number of nonzero eigenvalues of A, i.e. r (A)= n-1.