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If f : A rarr B is a bijective function,...

If f : A `rarr` B is a bijective function, then `f^(-1) of` is equal to

A

`fof^(-1)`

B

`f`

C

`f^(-1)`

D

`I_(A)` (the identity map of the set A)

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The correct Answer is:
To solve the problem, we need to determine what \( f^{-1}(f(x)) \) is when \( f: A \to B \) is a bijective function. ### Step-by-Step Solution: 1. **Understanding Bijective Functions**: A function \( f \) is bijective if it is both injective (one-to-one) and surjective (onto). This means that for every element \( y \) in set \( B \), there is exactly one element \( x \) in set \( A \) such that \( f(x) = y \). **Hint**: Recall the definitions of injective and surjective functions. 2. **Applying the Function**: Let \( y = f(x) \). Since \( f \) is a bijective function, we can find a unique \( x \) for every \( y \) in \( B \). **Hint**: Think about how the function maps elements from set \( A \) to set \( B \). 3. **Finding the Inverse**: Since \( f \) is bijective, it has an inverse function \( f^{-1} \). By definition of the inverse function, we have: \[ f^{-1}(y) = x \] Therefore, if we apply \( f^{-1} \) to both sides of \( y = f(x) \), we get: \[ f^{-1}(f(x)) = x \] **Hint**: Remember that applying the inverse function undoes the effect of the original function. 4. **Conclusion**: Thus, we conclude that: \[ f^{-1}(f(x)) = x \] This means that \( f^{-1}(f(x)) \) is the identity function on set \( A \). **Hint**: The identity function maps every element to itself. 5. **Final Result**: Therefore, the answer is that \( f^{-1}(f) \) is equal to the identity map on set \( A \). ### Summary: In conclusion, if \( f: A \to B \) is a bijective function, then: \[ f^{-1}(f(x)) = x \quad \text{for all } x \in A \] This confirms that \( f^{-1}(f) \) is the identity function on set \( A \).

To solve the problem, we need to determine what \( f^{-1}(f(x)) \) is when \( f: A \to B \) is a bijective function. ### Step-by-Step Solution: 1. **Understanding Bijective Functions**: A function \( f \) is bijective if it is both injective (one-to-one) and surjective (onto). This means that for every element \( y \) in set \( B \), there is exactly one element \( x \) in set \( A \) such that \( f(x) = y \). **Hint**: Recall the definitions of injective and surjective functions. ...
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