Question Details

A² – A + I = 0 then the inverse of A

Options

A

A

B

A + I

C

I - A

D

A - I

Correct Answer :

I - A

Solution :

The correct option is I - A.

We are given the matrix equation:
A2 − A + I = 0 where I is the identity matrix and 0 is the zero matrix.

To find the inverse of the matrix A (denoted as A−1), we can rearrange the terms to isolate the identity matrix I on one side of the equation:

I = A − A2

Next, we factor out the matrix A from the right-hand side. Since matrix multiplication is distributive over subtraction, we can write:

I = A ( I − A )

By definition, if two square matrices X and Y satisfy the relation XY=I, then Y is the multiplicative inverse of X (i.e., X−1=Y).

Comparing A(I−A)=I to this definition, we identify X=A and Y=I−A. Therefore, the inverse of A is:

A−1 = I − A

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