How do you simplify $cos^2((2pi)/9) - sin^2((2pi)/9)$?

Md Ariful Islam

বিএসসি(সিএসই) , এমবিএ(মার্কেটিং)

সফটওয়্যার ইঞ্জিনিয়ার Bissoy.com

4 views

2025-01-04 04:42

1 Answers

Md Ariful Islam

বিএসসি(সিএসই) , এমবিএ(মার্কেটিং)

সফটওয়্যার ইঞ্জিনিয়ার Bissoy.com

$cos^2A-sin^2A=cos 2A$
Here, $A = 2pi/9 radian=2X180/9 = 40^o$.
Answer is cos 2A = $cos(80^o)=0.17365$, nearly

4 views Answered 2024-04-02 09:48

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