This is from my homework, I was moving along nicely until I hit this problem, (there's another just like it right after this). I can't find reference for solving this in the chapter Im looking at. The answer is in the back of the book….-2911. Can someone explain this to me?(adsbygoogle = window.adsbygoogle || []).push({});

[tex]

||\mathbf{u}|| = 5\, and\: ||\mathbf{v}|| = 7; \,find\: (3\mathbf{u} - 8\mathbf{v}) \circ (3\mathbf{u} + 8\mathbf{v}).

[/tex]

I know that [itex]||\mathbf{u}||[/itex] is just the length of the vector, etc. I just don't know where to go from there.

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# Homework Help: Linear Algebra: Dot Product and Orthogonality

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