Principal Value of tan⁻¹{2sin(4cos⁻¹(√3/2))}

Evaluate: tan-1{2sin(4cos-1(√3/2))}

Solution:

Given:

\[ y = \tan^{-1}\left(2\sin\left(4\cos^{-1}\frac{\sqrt{3}}{2}\right)\right) \]

Step 1: Evaluate cos-1(√3/2)

\[ \cos^{-1}\left(\frac{\sqrt{3}}{2}\right) = \frac{\pi}{6} \]

Step 2: Substitute

\[ y = \tan^{-1}\left(2\sin\left(4 \cdot \frac{\pi}{6}\right)\right) = \tan^{-1}\left(2\sin\left(\frac{2\pi}{3}\right)\right) \]

Step 3: Evaluate sin(2π/3)

\[ \sin\frac{2\pi}{3} = \frac{\sqrt{3}}{2} \]

So,

\[ 2 \times \frac{\sqrt{3}}{2} = \sqrt{3} \]

Step 4: Final evaluation

\[ y = \tan^{-1}(\sqrt{3}) \]

Since principal value range of tan-1(x) is \((- \pi/2, \pi/2)\),

\[ \tan^{-1}(\sqrt{3}) = \frac{\pi}{3} \]

Final Answer:

Principal Value = \[ \frac{\pi}{3} \]

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