: Đẳng thức nào sau đây đúng ? A. cos4x – sin4x = 2-cos2x B. cos4x

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: Đẳng thức nào sau đây đúng ?
A. cos4x – sin4x = 2-cos2x B. cos4x – sin4x = 1+2sin2x

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8 votes

Explanation:

A. cos4x-sin4x=2-cos2x

Dimirsen Z answered May 22, 2022

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