Inverse of a Matrix with det=0

[ZedCar]

Homework Statement

What is the inverse of matrix A?
A=

(1) (2) (1)
(2) (-1) (2)
(1) (2) (1)

Homework Equations

The Attempt at a Solution

The determinant works out to be 0

The inverse is 1/determinant x adj(A)

Therefore the inverse is 1/0 x adj(A)

So is the answer to, what is the inverse, simply that it is undefined?

 

[Dick]

Homework Statement

What is the inverse of matrix A?
A=

(1) (2) (1)
(2) (-1) (2)
(1) (2) (1)

Homework Equations

The Attempt at a Solution

The determinant works out to be 0

The inverse is 1/determinant x adj(A)

Therefore the inverse is 1/0 x adj(A)

So is the answer to, what is the inverse, simply that it is undefined?

Sure. If a matrix has determinant zero then it doesn't have an inverse. It doesn't represent a 1-1 map that can be inverted.

 

[ZedCar]

Thank you