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

Sum and Difference Identities · Exercise 2

Is there only one way to evaluate $cos (\frac{5 π}{4}) ?$ Explain how to set up the solution in two different ways, and then compute to make sure they give the same answer.

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

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