P-1
Q-1
P-1Q-1 P
PQ P-1
Answer is Right!
Answer is Wrong!
The correct answer is $\boxed{\text{C. }P^{-1}Q^{-1}P}$.
Let $A$, $B$, and $C$ be matrices. Then, the following properties hold:
- $(AB)^{-1} = B^{-1}A^{-1}$
- $(A^{-1})^{-1} = A$
- $(AB)C = A(BC)$
- $A(B+C) = AB + AC$
- $(A+B)C = AC + BC$
- $A(kB) = k(AB)$
- $(kA)B = A(kB)$
- $A^2 = AA$
- $A(A^{-1}) = I$
- $(A^{-1})A = I$
In this case, we have $A = PQ$ and $B = P$. Substituting into the first property, we get $(PQ)^{-1}P = P^{-1}(PQ)^{-1}$. Applying the second property, we get $P^{-1}(PQ)^{-1} = (P^{-1}PQ)^{-1}$. Applying the third property, we get $(P^{-1}PQ)^{-1} = P^{-1}Q^{-1}$. Therefore, the product of matrices $(PQ)^{-1}P$ is $P^{-1}Q^{-1}P$.
Here is a brief explanation of each option:
- Option A: $P^{-1}$. This is not the correct answer because $P^{-1}$ is not the product of matrices $(PQ)^{-1}P$.
- Option B: $Q^{-1}$. This is not the correct answer because $Q^{-1}$ is not the product of matrices $(PQ)^{-1}P$.
- Option C: $P^{-1}Q^{-1}P$. This is the correct answer because it is the product of matrices $(PQ)^{-1}P$.
- Option D: $PQ P^{-1}$. This is not the correct answer because $PQ P^{-1}$ is not the product of matrices $(PQ)^{-1}P$.