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If `alpha` and `beta` are roots of equation `3/4"sin"((theta)/9)=sin^(3)theta+3sin^(3)((theta)/3)+9sin^(3)((theta)/9)+1/(4sqrt(2))` for `0lt theta lt (pi)/2`, then `tanalpha+tanbeta` is equal to

A

`2+sqrt(3)`

B

`3+sqrt(3)`

C

`3-sqrt(3)`

D

`2-sqrt(3)`

Text Solution

AI Generated Solution

The correct Answer is:
To solve the equation given in the problem, we will follow these steps: ### Step 1: Rewrite the given equation We start with the equation: \[ \frac{3}{4} \sin\left(\frac{\theta}{9}\right) = \sin^3(\theta) + 3\sin^3\left(\frac{\theta}{3}\right) + 9\sin^3\left(\frac{\theta}{9}\right) + \frac{1}{4\sqrt{2}} \] ### Step 2: Use the identity for \(\sin(3\theta)\) We know that: \[ \frac{1}{\sin(3\theta)} = \frac{3}{4} \sin\left(\frac{\theta}{9}\right) - \sin^3(\theta) - 3\sin^3\left(\frac{\theta}{3}\right) - 9\sin^3\left(\frac{\theta}{9}\right) \] This allows us to rewrite our equation in terms of \(\sin(3\theta)\). ### Step 3: Rearranging the equation Rearranging gives us: \[ \frac{1}{4\sin(3\theta)} = \frac{1}{4\sqrt{2}} \] Multiplying both sides by 4 results in: \[ \frac{1}{\sin(3\theta)} = \sqrt{2} \] ### Step 4: Solve for \(3\theta\) Taking the reciprocal gives: \[ \sin(3\theta) = \frac{1}{\sqrt{2}} \] The angles for which \(\sin\) equals \(\frac{1}{\sqrt{2}}\) are: \[ 3\theta = \frac{\pi}{4} + 2k\pi \quad \text{or} \quad 3\theta = \frac{3\pi}{4} + 2k\pi \] for integers \(k\). ### Step 5: Solve for \(\theta\) Dividing by 3 gives: \[ \theta = \frac{\pi}{12} + \frac{2k\pi}{3} \quad \text{or} \quad \theta = \frac{\pi}{4} + \frac{2k\pi}{3} \] Considering the range \(0 < \theta < \frac{\pi}{2}\), we find: - For \(k = 0\): \(\theta = \frac{\pi}{12}\) and \(\theta = \frac{\pi}{4}\). ### Step 6: Identify roots \(\alpha\) and \(\beta\) Thus, the roots are: \[ \alpha = \frac{\pi}{12}, \quad \beta = \frac{\pi}{4} \] ### Step 7: Calculate \(\tan\alpha + \tan\beta\) Now we compute: \[ \tan\alpha = \tan\left(\frac{\pi}{12}\right) \quad \text{and} \quad \tan\beta = \tan\left(\frac{\pi}{4}\right) \] We know: \[ \tan\left(\frac{\pi}{4}\right) = 1 \] Using the tangent half-angle formula: \[ \tan\left(\frac{\pi}{12}\right) = 2 - \sqrt{3} \] Thus: \[ \tan\alpha + \tan\beta = (2 - \sqrt{3}) + 1 = 3 - \sqrt{3} \] ### Final Answer Therefore, the value of \(\tan\alpha + \tan\beta\) is: \[ \boxed{3 - \sqrt{3}} \]

To solve the equation given in the problem, we will follow these steps: ### Step 1: Rewrite the given equation We start with the equation: \[ \frac{3}{4} \sin\left(\frac{\theta}{9}\right) = \sin^3(\theta) + 3\sin^3\left(\frac{\theta}{3}\right) + 9\sin^3\left(\frac{\theta}{9}\right) + \frac{1}{4\sqrt{2}} \] ...
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