A question in finding a invert of a certain operator

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Homework Help Overview

The discussion revolves around finding the inverse of a linear operator, denoted as A, under the condition that A² - A + I = 0. Participants are exploring the implications of this equation and the concept of an inverse operator.

Discussion Character

  • Conceptual clarification, Mathematical reasoning, Assumption checking

Approaches and Questions Raised

  • The original poster expresses uncertainty about how to proceed without a matrix and questions the meaning of the inverse operator. Some participants suggest focusing on the algebraic relationship provided and the definition of the inverse operator. There is a discussion about the implications of the equation A(I - A) = I and whether A^-1 can be expressed as I - A.

Discussion Status

Participants are actively engaging with the definitions and properties of the inverse operator. Some guidance has been offered regarding the relationship between A and its inverse, but there is no explicit consensus on the correctness of the proposed expression for A^-1. The conversation reflects a mix of interpretations and reasoning about the problem.

Contextual Notes

There is a lack of clarity regarding the original operator A and its properties, as well as the absence of a matrix representation, which may affect the discussion. Participants are navigating these constraints while attempting to derive the inverse.

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You are given that A2- A+ I= 0. Just basic algebra tells you that is the same as I= A- A2= A(I- A). Now, stop worrying about formulas, etc. and think about what A-1 means.
 
it means that if we take the image of a certain basis
and put it into the A^-1 we get the original basis

how its going to help me??

thought of certain solution of making some basic multiplication
operations

i got the resolt

A^-1=I-A
is it ok??
 
Last edited:
transgalactic said:
it means that if we take the image of a certain basis
and put it into the A^-1 we get the original basis
?? No, A-1 doesn't mean anything like that: it means the linear operation that "undoes" A. A-1Ax= x and AA-1x= x.

how its going to help me??

thought of certain solution of making some basic multiplication
operations

i got the resolt

A^-1=I-A
is it ok??
My point was that A(I- A)= I shows that I -A does exactly what we want of the inverse: AA-1= I. Since A(I-A)= I, (and inverses are unique), A-1= I- A.
 
so what is the answer??
what is the value of A^-1
 

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