Derive this identity from the sum and difference formulas for cosine:

Mathematics

1 answer:

DiKsa [7]3 years ago

4 0

Step-by-step explanation:

½ [cos(a − b) − cos(a + b)]

Using sum and difference formulas:

½ [cos a cos b + sin a sin b − (cos a cos b − sin a sin b)]

Distribute the negative:

½ (cos a cos b + sin a sin b − cos a cos b + sin a sin b)

Combine like terms:

½ (2 sin a sin b)

Simplify:

sin a sin b

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lakkis [162]

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Aleksandr-060686 [28]

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Answer:

A. ∠EAG and ∠BAC

Step-by-step explanation:

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2 years ago

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MariettaO [177]

Answer:

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Step-by-step explanation:

-6(x-3)

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