What is the dot product of <-5,2,8 ><5,2,8> and <-1,6,2 ><1,6,2>?

1 Answer
Aug 22, 2017

The answer is =33=33

Explanation:

The dot product of 22 vectors, veca= < x_1, x_2, x_3> a=<x1,x2,x3> and vecb = < y_1, y_2, y_3>b=<y1,y2,y3> is

veca.vecb=< x_1, x_2, x_3>.< y_1, y_2, y_3>a.b=<x1,x2,x3>.<y1,y2,y3>

=x_1y_1+x_2y_2+x_3y_3=x1y1+x2y2+x3y3

Therefore,

< -5, 2, 8>.< -1, 6, 2> = (-5*-1)+(2*6)+(8*2)<5,2,8>.<1,6,2>=(51)+(26)+(82)

=5+12+16=33=5+12+16=33