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The number of solution(s) of 2cos^(2)(x/...

The number of solution(s) of `2cos^(2)(x/2)sin^(2)x=x^(2)+1/x^(2), 0 le x le pi//2`, is/ are-

A

0

B

1

C

infinite

D

none of these

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To find the number of solutions of the equation \( 2\cos^2\left(\frac{x}{2}\right)\sin^2(x) = x^2 + \frac{1}{x^2} \) for \( 0 \leq x \leq \frac{\pi}{2} \), we will analyze both sides of the equation step by step. ### Step 1: Rewrite the left-hand side We start with the left-hand side of the equation: \[ y = 2\cos^2\left(\frac{x}{2}\right)\sin^2(x) \] Using the identity \( \cos^2\left(\frac{x}{2}\right) = \frac{1 + \cos(x)}{2} \), we can rewrite this as: \[ y = 2 \cdot \frac{1 + \cos(x)}{2} \cdot \sin^2(x) = (1 + \cos(x))\sin^2(x) \] ### Step 2: Analyze the right-hand side Now, consider the right-hand side: \[ x^2 + \frac{1}{x^2} \] This expression is always greater than or equal to 2 for \( x > 0 \) (by AM-GM inequality), and it approaches infinity as \( x \) approaches 0 or infinity. ### Step 3: Find the range of the left-hand side Next, we need to analyze the range of \( y = (1 + \cos(x))\sin^2(x) \) for \( 0 \leq x \leq \frac{\pi}{2} \): - At \( x = 0 \): \( y = (1 + \cos(0))\sin^2(0) = 2 \cdot 0 = 0 \) - At \( x = \frac{\pi}{2} \): \( y = (1 + \cos(\frac{\pi}{2}))\sin^2(\frac{\pi}{2}) = (1 + 0) \cdot 1 = 1 \) Since \( \cos(x) \) decreases from 1 to 0 and \( \sin^2(x) \) increases from 0 to 1, the product \( (1 + \cos(x))\sin^2(x) \) will vary between 0 and 1. ### Step 4: Find the range of the right-hand side Now, consider the right-hand side \( x^2 + \frac{1}{x^2} \): - As previously mentioned, this expression is always greater than or equal to 2 for \( x > 0 \). ### Step 5: Compare the ranges From the analysis: - The left-hand side \( y \) ranges from 0 to 1. - The right-hand side \( x^2 + \frac{1}{x^2} \) is always greater than or equal to 2. ### Conclusion Since the left-hand side can never reach the values of the right-hand side within the given range \( 0 \leq x \leq \frac{\pi}{2} \), there are no solutions to the equation. Thus, the number of solutions is: \[ \text{Number of solutions} = 0 \]

To find the number of solutions of the equation \( 2\cos^2\left(\frac{x}{2}\right)\sin^2(x) = x^2 + \frac{1}{x^2} \) for \( 0 \leq x \leq \frac{\pi}{2} \), we will analyze both sides of the equation step by step. ### Step 1: Rewrite the left-hand side We start with the left-hand side of the equation: \[ y = 2\cos^2\left(\frac{x}{2}\right)\sin^2(x) \] Using the identity \( \cos^2\left(\frac{x}{2}\right) = \frac{1 + \cos(x)}{2} \), we can rewrite this as: ...
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