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Verify A (a d j A) = (a d j A) A = |A|I ...

Verify `A (a d j A) = (a d j A) A = |A|I for [(2 ,3),(-4,-6)]`

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`A=[{:(2,3),(-4,-6):}]`
`A_(11)=(-1)^(1+2)(-4)=4`
`A_(21)=(-1)^(1+2)(-4)=4,`
`A_(21)=(-1)^(2+1)3=-3`,
`A_(22)=(-1)^(2+2)2=2`
`therefore" adj A"=[{:(-6,4),(-3,2):}]=[{:(-6,-3),(4,2):}]`
`"Now "|A|=[{:(2,3),(-4,-6):}]=-12+12=0`
`"A.(adk A)"=[{:(2,3),(-4,-6):}][{:(-6,-3),(4,2):}]`
`=[{:(-12+12,-6-3),(24-24,12-12):}]`
`[{:(0,0),(0,0):}]=0`
`"(adj A) A"=[{:(-6,-3),(4,2):}][{:(2,3),(-4,-6):}]`
`[{:(-12+12,-18+18),(8-8,12-12):}]`
`[{:(0,0),(0,0):}]=0`
|A| , I=0xxI=0
`therefore" "A.(adj A)=(adj A).A=|A|.I`
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NAGEEN PRAKASHAN ENGLISH-DETERMINANTS-Exercise 4.5
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