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Question
Find the co-factor of the element of the following matrix:
`[(-1, 2),(-3, 4)]`
Solution
Let A = `[(-1, 2),(-3, 4)]`
Here, a11 = −1, M11 = 4
∴ A11 = (−1)1+1(4) = 4
a12 = 2, M12 = −3
∴ A12 = (−1)1+2(−3) = 3
a21 = −3, M21 = 2
∴ A21 = (−1)2+1(2) = −2
a22 = 4, M22 = −1
∴ A22 = (−1)2+2(−1) = −1
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