Use the product-to-sum identities to rewrite the expression as the sum or difference of two functions. cos30cos5θ 2
1
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[cos8θ−cos2θ] cos 2
110 2
2
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[cos8θ−sin2θ] 2
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[cos2θ+cos8θ] Use the product-to-sum identities to rewrite the expression as the sum or difference of two functions. sin3θcos4θ sin(cos12θ 2
) 2
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[cos7θ+sinθ] 2
1
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[sin7θ−sinθ] 2
1
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[cos7θ−cosθ]