The eigen values of a matirx are the values L such that Ax = Lx where A is a matrix, x is a vector, and L is a constant.
The vector x is known as the eigenvector.
First, a small note: an m-by-n or m x n matrix has m rows and n columns. The eigenvalues λ of a matrix A are scalars such that Ax = λx for some nonzero x vector. The entries aij of a matrix A are...
If an identity matrix is the answer to a problem under matrix multiplication, then each of the two matrices is an inverse matrix of the other.
Let A by an nxn non-singular matrix, then A-1 is the inverse of A. Now (A-1 )-1 =A So the answer is yes.
To find the original matrix of an inverted matrix, simply invert it again. Consider A^-1^-1 = A^1 = A
No. A scalar matrix is a diagonal matrix whose main diagonal elements are the same. Only if the diagonal elements are all 1 is it an identity matrix.