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## Homework Statement

Let A =

a b

c d

A characteristic value of A (often called an eigenvalue) is denoted by λ and satisfies the relation

det(A - λI) = 0

Obtain the characteristics values of E =

1 -1

-1 1

## Homework Equations

Well I is the unit or identity matrix

1 0

0 1

## The Attempt at a Solution

I don't understand how E can be of any relation to what the question is asking. Does E = A?

det(A - λI) = 0

=> a - λ, b

c, d - λ = 0

super. ad + λ² - λa - λd + bc = 0

Let's presume for a second that their asking me that A = E

that means a=1, b = -1,c = -1,d = 1

=> 1 + λ² - λ(1-1) + 1 = 0

=? λ² = -2

that canny be though can it?

Any suggestions are welcomed!

Thanks

Tom