[Math] how do i tell if a vector is parallel to another vector in $\Bbb R^6$

linear algebravectors

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So far in my book I haven't learned any of the parallel or perpendicular notation.. so there must be some way to tell this answer that the book hasn't told me.. I looked back and there was nothing describing how to do it. How?

Best Answer

Others have already mentioned checking that one is a scalar multiple of another (and this is indeed the easiest way) but another possible method is to check if $$\mathbf{u}\boldsymbol{\cdot}\mathbf{v}=\Vert \mathbf{u}\Vert \Vert \mathbf{v} \Vert$$ If so, the vectors are parallel. If you're not working in $\mathbb{R}^n$, we can use $\langle \mathbf{u},\mathbf{v}\rangle$ instead.

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