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The equation 2sin(x/2).cos^2x+sin^2x=2si...

The equation `2sin(x/2).cos^2x+sin^2x=2sin(x/2)sin^2x+cos^2x` has a root for which

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To solve the equation \( 2\sin\left(\frac{x}{2}\right)\cos^2 x + \sin^2 x = 2\sin\left(\frac{x}{2}\right)\sin^2 x + \cos^2 x \), we can follow these steps: ### Step 1: Rearranging the Equation We start with the given equation: \[ 2\sin\left(\frac{x}{2}\right)\cos^2 x + \sin^2 x = 2\sin\left(\frac{x}{2}\right)\sin^2 x + \cos^2 x \] We can rearrange this to group similar terms: \[ 2\sin\left(\frac{x}{2}\right)\cos^2 x - 2\sin\left(\frac{x}{2}\right)\sin^2 x = \cos^2 x - \sin^2 x \] ### Step 2: Factoring Out Common Terms Notice that we can factor out \( 2\sin\left(\frac{x}{2}\right) \) from the left-hand side: \[ 2\sin\left(\frac{x}{2}\right)(\cos^2 x - \sin^2 x) = \cos^2 x - \sin^2 x \] ### Step 3: Setting Up the Equation Now, we can set up the equation: \[ 2\sin\left(\frac{x}{2}\right)(\cos^2 x - \sin^2 x) - (\cos^2 x - \sin^2 x) = 0 \] Factoring gives us: \[ (\cos^2 x - \sin^2 x)(2\sin\left(\frac{x}{2}\right) - 1) = 0 \] ### Step 4: Solving Each Factor Now we have two factors to solve: 1. \( \cos^2 x - \sin^2 x = 0 \) 2. \( 2\sin\left(\frac{x}{2}\right) - 1 = 0 \) **For the first factor:** \[ \cos^2 x = \sin^2 x \implies \tan^2 x = 1 \implies \tan x = \pm 1 \] Thus, \( x = n\pi + \frac{\pi}{4} \) or \( x = n\pi + \frac{3\pi}{4} \), where \( n \) is an integer. **For the second factor:** \[ 2\sin\left(\frac{x}{2}\right) = 1 \implies \sin\left(\frac{x}{2}\right) = \frac{1}{2} \] This gives: \[ \frac{x}{2} = \frac{\pi}{6} + 2k\pi \quad \text{or} \quad \frac{x}{2} = \frac{5\pi}{6} + 2k\pi \] Thus, \( x = \frac{\pi}{3} + 4k\pi \) or \( x = \frac{5\pi}{3} + 4k\pi \). ### Step 5: Conclusion The roots of the original equation are given by the solutions from both factors: - From \( \tan x = \pm 1 \): \( x = n\pi + \frac{\pi}{4} \) or \( x = n\pi + \frac{3\pi}{4} \) - From \( \sin\left(\frac{x}{2}\right) = \frac{1}{2} \): \( x = \frac{\pi}{3} + 4k\pi \) or \( x = \frac{5\pi}{3} + 4k\pi \)
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