What is the dot product of <9,4,1> and <-5,1,7 >?

Feb 5, 2016

$A . B = - 34$

Explanation:

$A = \left({A}_{i} , {A}_{j} , {A}_{k}\right)$
$B = \left({B}_{i} , {B}_{j} , {B}_{k}\right)$
$A . B = \left({A}_{i} . {B}_{i} + {A}_{j} . {B}_{j} + {A}_{k} . {B}_{k}\right)$
$A . B = \left(- 5.9 + 4.1 + 1.7\right)$
$A . B = - 45 + 4 + 7$
$A . B = - 34$