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Question: Answered & Verified by Expert
A=a2153112b2413561c2 and B=2a3522b8142c-3 are two matrices such that the sum of the principal diagonal elements of both A and B are equal, then the product of the principal diagonal elements of B is
MathematicsMatricesAP EAMCETAP EAMCET 2021 (19 Aug Shift 2)
Options:
  • A 4
  • B 0
  • C -4
  • D -12
Solution:
2062 Upvotes Verified Answer
The correct answer is: -4

Principal diagonal elements of A and B are a2, b2, c2 and 2a, 2b, 2c-3.

According to given condition, a2+b2+c2=2a+2b+2c-3

a2+1-2a+b2+1-2b+c2+1-2c=0

a-12+b-12+c-12=0

a-1=0, b-1=0, c-1=0

a=1, b=1, c=1

Now, 2a2b2c-3

Putting the values of a, b and c we get,

=2×2×-1=-4

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