Question

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

Answer 1

Answer:

❀ʀᴇǫᴜɪʀᴇᴅ ᴀɴsᴡᴇʀ:

According to this question

Given that

$cos(\frac{\pi}{7})\times cos(\frac{2\pi}{7})\times cos(\frac{4\pi}{7})$

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

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

Answer 2

Answer:

-1/8 is ur answer

Step-by-step explanation:

hope it helps u

explanation is in the attachment