Question 188994
If E is any n x n matrix with E^2 = Identity matrix, what is 
(Identity matrix + E)(Identity matrix - E)
= I -E + E - E^2 = I-E^2
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What is (Identity matrix - E)(Identity matrix + E)
= I + E - E - E^2 = I - E^2
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Cheers,
Stan H.
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