# What is the dot product of <-8,4,2 >  and <-3,1,6 > ?

Oct 29, 2016

$= 40$

#### Explanation:

It is easier to visualise what is happening if you write the vectors in vertical form. (imagine brackets around the stacks of numbers)

$\left(- 8\right)$ $\text{ } \left(- 3\right)$
$\text{ } \left(4\right)$ $\cdot$$\text{ } \left(1\right)$
$\text{ } \left(2\right)$ $\text{ } \left(6\right)$

now we take each of the rows, multiply them, and then add the products together,

$\left(\left(- 8\right) \cdot \left(- 3\right)\right) + \left(\left(4\right) \left(1\right)\right) + \left(\left(2\right) \left(6\right)\right)$

$= 24 + 4 + 12$

$= 40$