Question

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Answer 1

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Answer:

det(A·A^T) = (a² -1)²

Explanation:

The determinant of A is ...

det(A) = a·a -x·y = a² -1

The determinant of the transpose is the same, and the determinant of a matrix product is the product of the determinants.

`|A\cdot A^T|=|A|^2=\boxed{(a^2-1)^2=a^4-2a^2+1}`