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Question
If `A=[[2,3],[5,-2]]` then write A-1
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Solution
`A=[[2,3],[5,-2]]`
`therefore |A|=|[2,3],[5,-2]|=-4-15=-19ne 0`
So, A is a non-singular matrix. Therefore, it is invertible.
Now,
`C_11=−2, C_12=−5, C_21=−3, C_22=2`
`therefore adj A=[[-2,-5],[-3,2]]^T=[[-2,-3],[-5,2]]`
We know
`A^-1 =1/|A| adjA`
`therefore A^-1=1/(-19) [[-2,-3],[-5,2]]`
`=[[2/19,3/19],[5/19,-2/19]]`
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