Gauss Elimination
The inverse of a matrix is used for many different statistics. While you can add, subtract, or multiply matrices, you cannot divide them. However, if you multiple by the inverse of a matrix, this is equivalent to dividing. For example, if you divide 6 by 3 you get 2; however, you could also multiply 6 by the inverse of 3, 1/3, and get the same answer.
To find the inverse of a matrix, you basically append (not add) the identity to the matrix, then solve it so that the identity is on the left side. The contents of the right side of your matrix will be the inverse. For instance:[A] = [ [1 0] [2 1] ] (original matrix)[A] = [ [1 0] [2 1] | [1 0] [0 1] ] (appending the identity of a 2x2 matrix)(the bolded line is an imaginary divider)Next, you try to solve it so that the identity is shifted to the left side. The matrix's inverse will be the contents of the right.[A] = [ [1 0] [0 1] | [1 0] [2 -1] ][A]-1 = [ [1 0] [2 -1] ]
From Wolfram MathWorld: The inverse of a square matrix A, sometimes called a reciprocal matrix, is a matrix A-1 such that AA-1=I where I is the identity matrix.
The fact that the matrix does not have an inverse does not necessarily mean that none of the variables can be found.
A rectangular (non-square) matrix.
It is the matrix 1/3It is the matrix 1/3It is the matrix 1/3It is the matrix 1/3
it doesnt have an inverse since only square matrices have an inverse
The inverse of a matrix is used for many different statistics. While you can add, subtract, or multiply matrices, you cannot divide them. However, if you multiple by the inverse of a matrix, this is equivalent to dividing. For example, if you divide 6 by 3 you get 2; however, you could also multiply 6 by the inverse of 3, 1/3, and get the same answer.
To find the inverse of a matrix, you basically append (not add) the identity to the matrix, then solve it so that the identity is on the left side. The contents of the right side of your matrix will be the inverse. For instance:[A] = [ [1 0] [2 1] ] (original matrix)[A] = [ [1 0] [2 1] | [1 0] [0 1] ] (appending the identity of a 2x2 matrix)(the bolded line is an imaginary divider)Next, you try to solve it so that the identity is shifted to the left side. The matrix's inverse will be the contents of the right.[A] = [ [1 0] [0 1] | [1 0] [2 -1] ][A]-1 = [ [1 0] [2 -1] ]
(I-A)-1 is the Leontief inverse matrix of matrix A (nxn; non-singular).
In general, this is a complicated process. The matrix you start with must be a square matrix; the inverse will also be square, and of the same size. When you multiply a matrix by it's inverse, the result is the 'identity matrix' - another matrix of the same size as the first two. It has a diagonal row of 1's from top left to bottom right, and 0's everywhere else. The concept of the inverse in matrix arithmetic is similar to a reciprocal in multiplication: 3 x 3-1 = 3 x 1/3 = 1 When you multiply a number by it's reciprocal, you get '1'. In matrix math, AA-1 = I The identity matrix 'I' corresponds to the number 1. It is useful to learn how to find the inverse of a matrix with a graphing calculator, so that you can check your answer.
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.
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.
No. A square matrix has an inverse if and only if its determinant is nonzero.
From Wolfram MathWorld: The inverse of a square matrix A, sometimes called a reciprocal matrix, is a matrix A-1 such that AA-1=I where I is the identity matrix.
it is used to find the inverse of the matrix. inverse(A)= (adj A)/ mod det A
A singular matrix is a matrix which has no inverse because its determinant is zero. If you recall, the inverse of a matrix is1/ ad-bc multiplied by:[ d -b ][-c a ]If ad-bc = 0, then the inverse matrix would not exist because 1/0 is undefined, and hence it would be a singular matrix.E.g.[ 1 3][ 2 6]Is a singular matrix because 6x1-3x2 = 0.