Identifying cos^2 (wt+θ) in Signals Example Problem

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The discussion centers on the identity for cos^2(wt+θ), which is presented as cos^2(wt+θ) = [1 + cos(2wt + 2θ)]. Participants express confusion over this identity, suggesting it may be incorrect due to a missing factor of 2. The correct identity is clarified as cos(2x) = 2cos^2(x) - 1, indicating a potential misunderstanding in the original problem. The conversation emphasizes the importance of accurately applying trigonometric identities in signal processing examples. Accurate identification of these identities is crucial for solving related problems effectively.
Peon666
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While seeing a signals example problem, I encountered this:

cos^2 (wt+θ) = [1+cos(2wt+2θ)]

What identity is this?
 
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That doesn't seem right. Looks like they missed a factor of 2:

cos(2x) = 2cos^2(x) - 1
 

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