Proving Vector Space Identity: I-T Bijectivity

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Homework Help Overview

The discussion revolves around proving a property of a linear map in the context of vector spaces, specifically focusing on the condition that if \( T^2 = 0 \), then \( I - T \) is bijective, where \( I \) represents the identity matrix.

Discussion Character

  • Conceptual clarification, Mathematical reasoning

Approaches and Questions Raised

  • The original poster attempts to explore the relationship between \( I - T \) and \( I + T \) by manipulating the expression \( (I-T)(I+T) \) and questions the correctness of their approach.

Discussion Status

Some participants provide feedback on the original poster's manipulation, suggesting that it demonstrates the invertibility of \( I - T \). However, the discussion does not reach a consensus on the completeness of the proof or the implications of the findings.

Contextual Notes

The original poster expresses uncertainty about their initial steps and seeks guidance on how to proceed further in the proof.

Pearce_09
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Hello,
I am having trouble with particular algebra question. I don't know where to start and it would be greatly appreciated if someone could point me in the right direction.

Here is the questoin:

Let V be a vector space, where T is a linear map of V
prove if T^2 = 0 then I - T is bijective where I is the identity matrix

I tried (I-T)(I+T) = I - T^2 which equals I, but i am not sure where to go from here or if this even correct.
thanks for the time and help
regards,
adam
 
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You are done!
You just showed that [itex]I-T[/itex] is invertible/bijective by showing that [itex](I-T)(I+T) = (I+T)(I-T) = I[/itex]. Which means, by definition, [itex](I-T)^{-1} = (I+T)[/itex]
 
thx for the help incredible
 

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