The dot product [3 1 4]dot 2
-1
5 is.
My answer is 25, but I'm not sure. Thanks for any help given.
The dot product of two vectors $\displaystyle [x_1,\ x_2,\ x_3]$ and $\displaystyle [x_1,\ x_2,\ x_3]$ is:Originally Posted by kwtolley
$\displaystyle
\bold{x}\cdot \bold{y}=\sum_{i=1}^3 x_i y_i = x_1y_1+x_2y_2+x_3y_3
$.
In this case we have $\displaystyle \bold{x}=[3,1,4]$ and $\displaystyle \bold{y}=[2,-1,5]$, so:
$\displaystyle
\bold{x}\cdot \bold{y}= 3\times 2+1\times (-5)+4\times 5=21
$.
RonL