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Explain why cos(−3π4)=cos(5π4).

1 Answer

11 votes

Answer:

See below

Explanation:

Think about what happens when you rotate around a circle
-(3\pi)/(4) radians. This means that you are going clockwise
-(3\pi)/(4) radians.

Likewise, if you went
(5\pi)/(4) radians counterclockwise, you'd end up in the same place, so the cosine values must be the same.

Explain why cos(−3π4)=cos(5π4).-example-1
User Jeff Miller
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