Sum and Difference formulas

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5.4

• Sum and Difference formulas

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Quick Review

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Quick Review Solutions
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What youll learn about

• Cosine of a Difference
• Cosine of a Sum
• Sine of a Difference or Sum
• Tangent of a Difference or Sum
• Verifying a Sinusoid Algebraically
• and why
• These identities provide clear examples of how
  different the
• algebra of functions can be from the algebra of
  real numbers.

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Cosine of a Sum or Difference

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Example Using the Cosine-of-a-Difference Identity

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Example Using the Cosine-of-a-Difference Identity

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Sine of a Sum or Difference

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Example Using the Sum and Difference Formulas

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Example Using the Sum and Difference Formulas

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Tangent of a Difference of Sum