(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

Show that the dot product of vectors a and b is equal to 1/4|a+b|^2 - 1/4|a-b|^2

2. Relevant equations

a dot b = |a||b|cos(theta)

a dot b = a1b1 + a2b2 + ...

3. The attempt at a solution

I've tried using the combination of the cosine law and those two above dot product equations and I have gotten no where. Any help would be greatly appreciated. (:

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# Homework Help: The Dot Product Expansion

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