cos(2θ) = cos2 θ - ________ = _________ - 1 = 1 - ______.
Added by Elizabeth D.
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Using the double angle formula for cosine, we have: cos(2θ) = cos²θ - sin²θ Show more…
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$\cos (2 \theta)=\cos ^{2} \theta-$ ______ - = _______ - 1 = 1 - _______.
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