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Matrices

Question
CBSEENMA12034276

If space straight A equals space space open square brackets table row 3 cell space space space 2 end cell cell space space 0 end cell row 1 cell space space 4 end cell cell space space 0 end cell row 0 cell space space space 0 space end cell 5 end table close square brackets space comma space show space that space straight A squared space minus 7 straight A space plus space 10 space straight I subscript 3 space end subscript equals space 0

Solution
Here space straight A equals space space open square brackets table row 3 cell space space space 2 end cell cell space space 0 end cell row 1 cell space space 4 end cell cell space space 0 end cell row 0 cell space space space 0 space end cell 5 end table close square brackets
therefore space space space space straight A squared equals space open square brackets table row 3 cell space space space 2 end cell cell space space 0 end cell row 1 cell space space 4 end cell cell space space 0 end cell row 0 cell space space space 0 space end cell 5 end table close square brackets space open square brackets table row 3 cell space space space 2 end cell cell space space 0 end cell row 1 cell space space 4 end cell cell space space 0 end cell row 0 cell space space space 0 space end cell 5 end table close square brackets
space space space space space space space space space space space space equals space open square brackets table row cell 9 plus 2 plus 0 end cell cell 6 plus 8 plus 0 end cell cell 0 plus 0 plus 0 end cell row cell 3 plus 4 plus 0 space space space end cell cell 2 plus 16 plus 0 end cell cell 0 plus 0 plus 0 end cell row cell 0 plus 0 plus 0 end cell cell 0 plus 0 plus 0 end cell cell space space 0 plus 0 plus 25 end cell end table close square brackets space equals space open square brackets table row 11 cell space space 14 end cell cell space space 0 end cell row 7 cell space space space 18 end cell cell space 0 end cell row 0 cell space space 0 end cell cell space 25 end cell end table close square brackets
therefore space space space space space straight A squared space minus 7 straight A space plus 10 space straight I subscript 3 equals space open square brackets table row 14 14 0 row 7 8 0 row 0 0 25 end table close square brackets space space minus 7 space space open square brackets table row 3 cell space 2 end cell cell space 0 end cell row 1 cell space 4 end cell cell space 0 end cell row 0 cell space 0 space end cell 5 end table close square brackets space plus 10 space open square brackets table row 1 cell space space space space space 0 end cell cell space space space space 0 end cell row 0 cell space space space space 1 end cell cell space space space 0 end cell row 0 cell space space space space 0 end cell cell space space space 1 end cell end table close square brackets
space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space equals space open square brackets table row cell 11 minus 21 plus 10 end cell cell 14 minus 14 plus 0 end cell cell 0 plus 0 plus 0 end cell row cell 7 minus 7 plus 0 end cell cell 18 minus 28 plus 10 end cell cell 0 plus 0 plus 0 end cell row cell 0 plus 0 plus 0 end cell cell 0 plus 0 plus 0 end cell cell 25 minus 35 plus 10 end cell end table close square brackets space equals space open square brackets table row 0 cell space space space space 0 end cell cell space space space 0 end cell row 0 cell space space space space 0 end cell cell space space space 0 end cell row 0 cell space space space space 0 end cell cell space space space 0 end cell end table close square brackets
therefore space space space space straight A squared minus 7 straight A plus 10 space straight I subscript 3 space equals straight O

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