OpenStax, Algebra and Trigonometry 2e §9.2 Sum and Difference Identities · Example 8 · Trigonometry · Compound & multiple angles

Verifying an Identity Involving Sine

Verify the identity $s in (α + β) + s in (α - β) = 2 s in α cos β .$

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OpenStax, Algebra and Trigonometry 2e · §9.2 Sum and Difference Identities · Example 8

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