Section 11.3 : Dot Product
1. Determine the dot product, \(\vec a\centerdot \vec b\) if \(\vec a = \left\langle {9,5, - 4,2} \right\rangle \) and \(\vec b = \left\langle { - 3, - 2,7, - 1} \right\rangle \).
Show SolutionNot really a whole lot to do here. We just need to run through the definition of the dot product.
\[\vec a\centerdot \vec b = \left( 9 \right)\left( { - 3} \right) + \left( 5 \right)\left( { - 2} \right) + \left( { - 4} \right)\left( 7 \right) + \left( 2 \right)\left( { - 1} \right) = \require{bbox} \bbox[2pt,border:1px solid black]{{ - 67}}\]