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Determine the smallest positive value of `x` which satisfy the equation `sqrt(1+sin2x)-sqrt(2)cos3x=0`

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To solve the equation \( \sqrt{1 + \sin 2x} - \sqrt{2} \cos 3x = 0 \), we will follow these steps: ### Step 1: Rearranging the Equation Start by rearranging the equation to isolate the square root: \[ \sqrt{1 + \sin 2x} = \sqrt{2} \cos 3x \] ### Step 2: Squaring Both Sides Next, square both sides to eliminate the square root: \[ 1 + \sin 2x = 2 \cos^2 3x \] ### Step 3: Using Trigonometric Identities Recall that \( \sin 2x = 2 \sin x \cos x \) and \( \cos^2 3x = 1 - \sin^2 3x \). Substitute these identities into the equation: \[ 1 + 2 \sin x \cos x = 2(1 - \sin^2 3x) \] This simplifies to: \[ 1 + 2 \sin x \cos x = 2 - 2 \sin^2 3x \] ### Step 4: Rearranging the Equation Rearranging gives: \[ 2 \sin x \cos x + 2 \sin^2 3x - 1 = 0 \] ### Step 5: Simplifying Further Divide the entire equation by 2: \[ \sin x \cos x + \sin^2 3x - \frac{1}{2} = 0 \] ### Step 6: Using the Double Angle Identity Recall that \( \sin x \cos x = \frac{1}{2} \sin 2x \): \[ \frac{1}{2} \sin 2x + \sin^2 3x - \frac{1}{2} = 0 \] Multiplying through by 2 gives: \[ \sin 2x + 2 \sin^2 3x - 1 = 0 \] ### Step 7: Solving for \( \sin 2x \) Rearranging gives: \[ \sin 2x = 1 - 2 \sin^2 3x \] ### Step 8: Using the Identity for \( \sin 2x \) Using the identity \( \sin 2x = 2 \sin x \cos x \), we can set up the equation: \[ 2 \sin x \cos x = 1 - 2 \sin^2 3x \] ### Step 9: Finding Values of \( x \) To find the smallest positive value of \( x \), we can analyze the equation further. We can set \( \sin 2x = 0 \) or \( 1 - 2 \sin^2 3x = 0 \) to find potential solutions. 1. **For \( \sin 2x = 0 \)**: \[ 2x = n\pi \implies x = \frac{n\pi}{2} \] 2. **For \( 1 - 2 \sin^2 3x = 0 \)**: \[ 2 \sin^2 3x = 1 \implies \sin^2 3x = \frac{1}{2} \implies \sin 3x = \pm \frac{1}{\sqrt{2}} = \pm \frac{\sqrt{2}}{2} \] This gives: \[ 3x = \frac{\pi}{4} + k\pi \implies x = \frac{\pi}{12} + \frac{k\pi}{3} \] ### Step 10: Finding the Smallest Positive Solution Now we need to find the smallest positive \( x \) from both sets of solutions: - From \( x = \frac{n\pi}{2} \), the smallest positive value is \( \frac{\pi}{2} \) (for \( n=1 \)). - From \( x = \frac{\pi}{12} + \frac{k\pi}{3} \), for \( k=0 \), we have \( \frac{\pi}{12} \) and for \( k=1 \), we have \( \frac{5\pi}{12} \). The smallest positive value among \( \frac{\pi}{2}, \frac{\pi}{12}, \frac{5\pi}{12} \) is: \[ \frac{\pi}{12} \] ### Final Answer Thus, the smallest positive value of \( x \) that satisfies the equation is: \[ \boxed{\frac{\pi}{12}} \]

To solve the equation \( \sqrt{1 + \sin 2x} - \sqrt{2} \cos 3x = 0 \), we will follow these steps: ### Step 1: Rearranging the Equation Start by rearranging the equation to isolate the square root: \[ \sqrt{1 + \sin 2x} = \sqrt{2} \cos 3x \] ...
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