Find x such that the matrix is equal to its own inverse. A = left[3 x , -2 -3right]

asked 2021-02-25
Find x such that the matrix is equal to its own inverse.
\(A = \left[3 x , -2 -3\right]\)

Answers (1)

When you multiply this matrix by itself, the first element is 9-2x that has to be equal to 1.
So the answer \(x = 4\) then the matrix is its own inverse!
when \(x = 4\) then
\(\begin{bmatrix}1 & 0 \\0 & 1 \end{bmatrix}\)
Result: \(x = 4\)
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