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Which of the following is not a property of invertible matrices if A and B are matrices of the same order?
  • a)
    (AB)-1 = A-1 B-1
  • b)
    (AA-1) = (A-1 A) = I
  • c)
    (AB)-1 = B-1 A-1
  • d)
    AB = BA = I
Correct answer is option 'A'. Can you explain this answer?
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Which of the following is not a property of invertible matrices if A a...
Properties of Invertible Matrices:

1. (AA-1) = (A-1 A) = I
2. AB = BA = I
3. (A-1)-1 = A
4. (kA)-1 = (1/k)A-1, where k is a non-zero scalar
5. (AB)-1 = B-1 A-1

Explanation:

Option A states that (AB)-1 = A-1 B-1, which is not a property of invertible matrices. This statement is false because in general, (AB)-1 ≠ A-1 B-1.

To see why this is true, consider the case where A and B are both 2x2 matrices:

A = [a b]
[c d]

B = [e f]
[g h]

Then AB is given by:

AB = [ae+bg af+bh]
[ce+dg cf+dh]

The inverse of AB, assuming it exists, is given by:

(AB)-1 = 1/det(AB) [dh -bh -cf af]
[-dg ae ce -af]

where det(AB) = (ae+bg)(cf+dh)-(af+bh)(ce+dg)

On the other hand, the inverse of A and B are given respectively by:

A-1 = 1/det(A) [d -b]
[-c a]

B-1 = 1/det(B) [h -f]
[-g e]

where det(A) = ad-bc and det(B) = eh-fg

Now, if we compute A-1 B-1, we get:

A-1 B-1 = 1/det(A)det(B) [(dh-bgf-eh+fg) -(bh-ae-hf+cf)]
[(-dg+ce+bg-af) (ag-ce-df+ae)]

Notice that A-1 B-1 is not equal to (AB)-1 in general, unless A and B commute (i.e. AB = BA).

Therefore, option A is not a property of invertible matrices.
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Which of the following is not a property of invertible matrices if A a...
 (AB)-1 = A-1 B-1 is incorrect. The correct formula is (AB)-1 = B-1 A-1. B-1 A-1 ≠  A-1 B-1 as matrix multiplication is not commutative.
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Which of the following is not a property of invertible matrices if A and B are matrices of the same order?a)(AB)-1 = A-1 B-1b)(AA-1) = (A-1 A) = Ic)(AB)-1 = B-1 A-1d)AB = BA = ICorrect answer is option 'A'. Can you explain this answer?
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Which of the following is not a property of invertible matrices if A and B are matrices of the same order?a)(AB)-1 = A-1 B-1b)(AA-1) = (A-1 A) = Ic)(AB)-1 = B-1 A-1d)AB = BA = ICorrect answer is option 'A'. Can you explain this answer? for Class 12 2024 is part of Class 12 preparation. The Question and answers have been prepared according to the Class 12 exam syllabus. Information about Which of the following is not a property of invertible matrices if A and B are matrices of the same order?a)(AB)-1 = A-1 B-1b)(AA-1) = (A-1 A) = Ic)(AB)-1 = B-1 A-1d)AB = BA = ICorrect answer is option 'A'. Can you explain this answer? covers all topics & solutions for Class 12 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for Which of the following is not a property of invertible matrices if A and B are matrices of the same order?a)(AB)-1 = A-1 B-1b)(AA-1) = (A-1 A) = Ic)(AB)-1 = B-1 A-1d)AB = BA = ICorrect answer is option 'A'. Can you explain this answer?.
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