- #1
Rijad Hadzic
- 321
- 20
Homework Statement
Prove that [itex] [adj(A)]^{-1} = adj(A^{-1}) [/itex]
Homework Equations
The Attempt at a Solution
Ok. So if
[itex]1/det(a) * adj(a) = A^{-1} [/itex] is true,
then [itex] adj(A) = A^{-1} det(A) [/itex]
then
[itex] [adj(A)]^{-1} = 1/det(A^{-1}) * adj(A^{-1}) * det(A) [/itex]
now the statement would be proved if det(A) and det(A^{-1}) were both = 1, but it doesn't say that's the case in the problem. How would I go about completing this?
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