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

Prove that |[tex]\vec{A}[/tex]|^{2}+|[tex]\vec{B}[/tex]|^{2}equals to [tex]\frac{1}{2}[/tex](|[tex]\vec{A}[/tex]+[tex]\vec {B}[/tex]|^{2}+|[tex]\vec{A}[/tex]-[tex]\vec{B}[/tex]|^{2})

2. Relevant equations

Perhaps the triangle inequality? I am not sure.

3. The attempt at a solution

I have no idea how to approach this question. Please help me with clear explanations. Thank you.

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# What does this vector equal to?

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