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Pand Q are two square matrices of the same order. Which of the following statement(s) is/are correct?
  • a)
    If P a n d Q are invertible, then [PQ]-1 = Q-1P-1.
  • b)
    If P and Q are invertible, then [PQ]-1 = P-1Q-1.
  • c)
    If P and Q are invertible, then [QP]-1 = P-1Q-1.
  • d)
    If P and Q are not invertible, then [PQ]-1 = Q-1P-1.
Correct answer is option 'A,C'. Can you explain this answer?
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Pand Q are two square matrices of the same order. Which of the followi...
Answer:

Statement a: If P and Q are invertible, then [PQ]-1 = Q-1P-1.
Statement c: If P and Q are invertible, then [QP]-1 = P-1Q-1.

To determine the correctness of these statements, let's consider the properties of invertible matrices and matrix multiplication.

Invertible matrices:
- An invertible matrix, also known as a non-singular matrix, is a square matrix that has an inverse.
- If a matrix A is invertible, then A-1 is the inverse of A, such that A * A-1 = A-1 * A = I, where I is the identity matrix.
- Invertible matrices have the property that their determinant is non-zero.

Matrix multiplication:
- Matrix multiplication is not commutative, i.e., AB ≠ BA in general.
- However, for invertible matrices A and B, AB and BA are both invertible, and their inverses are related as (AB)-1 = B-1A-1 and (BA)-1 = A-1B-1.

Now, let's analyze each statement:

Statement a: If P and Q are invertible, then [PQ]-1 = Q-1P-1.
This statement is correct. According to the properties of matrix multiplication and invertible matrices, we have:
[PQ]-1 = Q-1P-1 (Using the property (AB)-1 = B-1A-1)

Statement c: If P and Q are invertible, then [QP]-1 = P-1Q-1.
This statement is also correct. By applying the same property of matrix multiplication and invertible matrices, we have:
[QP]-1 = P-1Q-1

Therefore, both statements a and c are correct.

Conclusion:
- If P and Q are invertible matrices, then both [PQ]-1 = Q-1P-1 and [QP]-1 = P-1Q-1 hold true.
- In general, the order of multiplication matters in matrix multiplication, and the inverses of matrices should be multiplied in the reverse order to obtain the inverse of the product matrix.
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Pand Q are two square matrices of the same order. Which of the followi...
∵ P and Q are not invertible, so
[PQ]-1 ≠ Q-1 P-1 
If P and Q are invertible then,
[OP]-1 = P-1 Q-1 
If P and Q are invertible, then
[PQ]-1 = Q-1 P-1.
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Pand Q are two square matrices of the same order. Which of the following statement(s) is/are correct?a)If P a n d Q are invertible, then [PQ]-1 = Q-1P-1.b)If P and Q are invertible, then [PQ]-1 = P-1Q-1.c)If P and Q are invertible, then [QP]-1 = P-1Q-1.d)If P and Q are not invertible, then [PQ]-1 = Q-1P-1.Correct answer is option 'A,C'. Can you explain this answer?
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