Question

What is the dot product of `<5,6,-3 >` and `<-4,8,-5 >`?

Answer 1

`43`

Explanation:

The classic euclidian scalar product is given by the following formula : `AA x=(x_1,...,x_n),y=(y_1,...,y_n) in RR^n : x.y = sum_(i=1)^n x_iy_i`.

We apply it here : `(5,6,-3).(-4,8,-5) = 5*(-4) + 6*8 + (-5)*(-3) = -20 + 48 + 15 = 43`