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Statement:1: If sum (r=1)^(n) sin(x(r)) ...

Statement:1: If `sum _(r=1)^(n) sin(x_(r)) = n`, then `sum_(n=1)^(n) cot (x_(r)) =n`. And Statement-2: The number of solutions of the equation `cosx =x` is 1.

A

(a)Statement-1 is true, Statement-2 is true, Statement-2 is a correct explanation for statement-11

B

(b)Statement-1 is true, Statement-2 is true, Statement-2 is not a correct expanation for statement-11

C

(c)Statement-1 is True, Statement-2 is false

D

(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 the two statements provided and determine their validity. ### Step 1: Analyze Statement 1 The first statement is: If \( \sum_{r=1}^{n} \sin(x_r) = n \), then \( \sum_{r=1}^{n} \cot(x_r) = n \). 1. From the equation \( \sum_{r=1}^{n} \sin(x_r) = n \), we can infer that each \( \sin(x_r) \) must be equal to 1, since the maximum value of \( \sin(x) \) is 1. This implies that: \[ \sin(x_r) = 1 \quad \text{for all } r \] Therefore, \( x_r = \frac{\pi}{2} + 2k\pi \) for some integer \( k \). 2. If \( \sin(x_r) = 1 \), then \( \cot(x_r) = \frac{\cos(x_r)}{\sin(x_r)} = \frac{0}{1} = 0 \). 3. Thus, we have: \[ \sum_{r=1}^{n} \cot(x_r) = \sum_{r=1}^{n} 0 = 0 \] This means that \( \sum_{r=1}^{n} \cot(x_r) \neq n \) unless \( n = 0 \). **Conclusion for Statement 1**: The statement is false. ### Step 2: Analyze Statement 2 The second statement is: The number of solutions of the equation \( \cos(x) = x \) is 1. 1. To analyze this, we can consider the functions \( y = \cos(x) \) and \( y = x \) graphically. The function \( \cos(x) \) oscillates between -1 and 1, while the line \( y = x \) is a straight line. 2. The function \( \cos(x) \) is continuous and decreases from 1 to -1 as \( x \) increases from 0 to \( \pi \). 3. The intersection points of \( y = \cos(x) \) and \( y = x \) can be found by observing that: - At \( x = 0 \), \( \cos(0) = 1 \) and \( 0 < 1 \). - At \( x = 1 \), \( \cos(1) \) is approximately 0.54, and \( 1 > 0.54 \). - At \( x = \pi/2 \), \( \cos(\pi/2) = 0 \) and \( \pi/2 \approx 1.57 > 0 \). 4. Since \( \cos(x) \) is continuous and decreases from 1 to -1, and the line \( y = x \) is increasing, there will be exactly one intersection point in the interval \( [0, 1] \). **Conclusion for Statement 2**: The statement is true. ### Final Conclusion - Statement 1 is false. - Statement 2 is true. Thus, the correct option is that Statement 1 is false and Statement 2 is true.
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