1.

The value of cos(π/7) * cos(2π/7) * cos(4π/7) is

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Answer:

❀ʀᴇǫᴜɪʀᴇᴅ ᴀɴsᴡᴇʀ:

ACCORDING to this question

Given that

cos(\frac{\pi}{7})\times cos(\frac{<klux>2</klux>\pi}{7})\times cos(\frac{4\pi}{7})

Formula, SIN 2X = 2 sinx cosx

cosx =\frac{sin \: 2x}{2 \: sin \: x}

so,

cos(\frac{\pi}{7})\times cos(\frac{2\pi}{7})\times cos(\frac{4\pi}{7})= \frac{sin \frac{2\pi}{7}\times sin \frac{4\pi}{7}\times sin \frac{8\pi}{7}\times }{2sin \frac{\pi}{7}\times 2sin \frac{2\pi}{7}\times 2sin \frac{4\pi}{7}}

from next it is in the attachment

\sf\blue{hope \: this \: helps \: you!! \: }


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