Immanuel G.

asked • 03/24/18

proving the sum and difference equation for cosine

Suppose that 𝒗 and 𝒘 are unit vectors. If the angle between 𝒗 and 𝒊̂ is 𝛼 and that between 𝒘 and 𝒊̂ is 𝛽, prove that cos(𝛼−𝛽)=cos𝛼cos𝛽+sin𝛼sin𝛽

1 Expert Answer


Jeffrey K. answered • 10/02/20

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