- A1/8
- B1/4
- C1/16
- D√3/8
Step-by-Step Solution
Multiply and divide by sin 20°: using 2 sin cos = sin three times, 8 sin 20° cos 20° cos 40° cos 80° = sin 160° = sin 20°. So the product is 1/8.
Answer: A) 1/8
Find the value of cos 20° cos 40° cos 80°.
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