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AP EAMCET202419 May 2024Evening ShiftMathematicsDeterminantsActual

If A= [ array cc 1 & 2 -2 & -5 array ] and A^2+ A=2 I for some , , R then + =

Options

  1. A7
  2. B10
  3. C12
  4. D5

Correct answer

B. 10

Step-by-step solution

aligned & Given, A= [ array cc 1 & 2 -2 & -5 array ] , So, A^2-(-5+1) A+(-5+4) I=0 & A^2+4 A=I 2 A^2+8 A=2 I aligned If we compare with A^2+ A=2 I , we get =2, =8 + =10 .

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