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Statement-1 : If f(x) and g(x) are one-o...

Statement-1 : If f(x) and g(x) are one-one functions then f(g(x)) and g(f(x)) is also a one-one function.
and
Statement-2 The composite function of two one-one function may or many not be one-one.

A

Statement-1 is True, Statement-2 is True, Statement-2 is a correct explanation for Statement-1.

B

Statement-1 is True, Statement-2 is True, Statement-2 is NOT a correct explanation for Statement-1.

C

Statement -1 is True, Statement -2 is False

D

Statement -1 is False, Statement -2 is True

Text Solution

AI Generated Solution

The correct Answer is:
To solve the given statements regarding the one-one functions \( f(x) \) and \( g(x) \), we will analyze both statements step by step. ### Step 1: Understanding One-One Functions A function \( f(x) \) is said to be one-one (or injective) if it satisfies the condition: \[ f(x_1) = f(x_2) \implies x_1 = x_2 \] This means that different inputs lead to different outputs. ### Step 2: Analyzing Statement 1 **Statement 1:** If \( f(x) \) and \( g(x) \) are one-one functions, then \( f(g(x)) \) and \( g(f(x)) \) are also one-one functions. 1. **Consider \( f(g(x_1)) = f(g(x_2)) \)**: - Since \( f \) is one-one, we can conclude that: \[ g(x_1) = g(x_2) \] 2. **Now, since \( g \) is also one-one**: - From \( g(x_1) = g(x_2) \), we can conclude that: \[ x_1 = x_2 \] 3. **Thus, we have shown that**: \[ f(g(x_1)) = f(g(x_2)) \implies x_1 = x_2 \] - Therefore, \( f(g(x)) \) is one-one. 4. **Now, consider \( g(f(x_1)) = g(f(x_2)) \)**: - Similarly, since \( g \) is one-one, we have: \[ f(x_1) = f(x_2) \] 5. **And since \( f \) is one-one**: - From \( f(x_1) = f(x_2) \), we can conclude that: \[ x_1 = x_2 \] 6. **Thus, we have shown that**: \[ g(f(x_1)) = g(f(x_2)) \implies x_1 = x_2 \] - Therefore, \( g(f(x)) \) is also one-one. ### Conclusion for Statement 1: Since both \( f(g(x)) \) and \( g(f(x)) \) are shown to be one-one, **Statement 1 is true**. ### Step 3: Analyzing Statement 2 **Statement 2:** The composite function of two one-one functions may or may not be one-one. - From our analysis in Statement 1, we have established that the composition of two one-one functions is always one-one. - Therefore, the assertion that it "may or may not be one-one" is incorrect. ### Conclusion for Statement 2: Since we have proven that the composition of two one-one functions is always one-one, **Statement 2 is false**. ### Final Answer: - **Statement 1 is true.** - **Statement 2 is false.**
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