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Statement-1f(x)=(sin x)/(x) lt 1 for 0 l...

Statement-1`f(x)=(sin x)/(x) lt 1 for 0 lt x lt pi/2`
Statement -2 `f(x)=(sin x)/(x)` is decreasing function on `(0,pi//2)`

A

Statement-1 True statement -1 is True,Statement -2 is True statement -2 is a correct explanation for Statement-4

B

Statement-1 True statement -1 is True,Statement -2 is True statement -2 is not a correct explanation for Statement-4

C

Statement-1 True 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 problem, we need to analyze both statements regarding the function \( f(x) = \frac{\sin x}{x} \) for \( 0 < x < \frac{\pi}{2} \). ### Step 1: Analyze Statement 1 **Statement 1:** \( f(x) = \frac{\sin x}{x} < 1 \) for \( 0 < x < \frac{\pi}{2} \). To prove this statement, we can evaluate the behavior of \( \sin x \) and \( x \) in the interval \( (0, \frac{\pi}{2}) \). 1. **Behavior of \( \sin x \)**: The function \( \sin x \) is increasing in the interval \( (0, \frac{\pi}{2}) \) and takes values from \( 0 \) to \( 1 \). 2. **Behavior of \( x \)**: The function \( x \) is also increasing in the interval \( (0, \frac{\pi}{2}) \) and takes values from \( 0 \) to \( \frac{\pi}{2} \). Since \( \sin x < x \) for \( 0 < x < \frac{\pi}{2} \), we can conclude: \[ \frac{\sin x}{x} < 1 \quad \text{for } 0 < x < \frac{\pi}{2}. \] Thus, Statement 1 is true. ### Step 2: Analyze Statement 2 **Statement 2:** \( f(x) = \frac{\sin x}{x} \) is a decreasing function on \( (0, \frac{\pi}{2}) \). To determine if \( f(x) \) is decreasing, we can find the derivative \( f'(x) \): 1. **Differentiate \( f(x) \)** using the quotient rule: \[ f'(x) = \frac{x \cos x - \sin x}{x^2}. \] 2. **Analyze the numerator**: We need to check the sign of \( x \cos x - \sin x \) in the interval \( (0, \frac{\pi}{2}) \). - At \( x = 0 \), \( f'(0) \) is not defined, but we can analyze the limit. - As \( x \) approaches \( 0 \), \( \sin x \) behaves like \( x \), and \( \cos x \) approaches \( 1 \). Thus, \( \sin x < x \) implies \( x \cos x - \sin x < 0 \). - For \( 0 < x < \frac{\pi}{2} \), \( \cos x \) is positive, and since \( \sin x < x \), we have \( x \cos x < \sin x \). Thus, \( x \cos x - \sin x < 0 \) implies \( f'(x) < 0 \), indicating that \( f(x) \) is decreasing on \( (0, \frac{\pi}{2}) \). ### Conclusion Both statements are true: - Statement 1 is true: \( f(x) < 1 \) for \( 0 < x < \frac{\pi}{2} \). - Statement 2 is true: \( f(x) \) is a decreasing function on \( (0, \frac{\pi}{2}) \). ### Final Answer Both statements are true, and Statement 2 provides the correct explanation for Statement 1.

To solve the problem, we need to analyze both statements regarding the function \( f(x) = \frac{\sin x}{x} \) for \( 0 < x < \frac{\pi}{2} \). ### Step 1: Analyze Statement 1 **Statement 1:** \( f(x) = \frac{\sin x}{x} < 1 \) for \( 0 < x < \frac{\pi}{2} \). To prove this statement, we can evaluate the behavior of \( \sin x \) and \( x \) in the interval \( (0, \frac{\pi}{2}) \). 1. **Behavior of \( \sin x \)**: The function \( \sin x \) is increasing in the interval \( (0, \frac{\pi}{2}) \) and takes values from \( 0 \) to \( 1 \). ...
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