Diketahui titik A(0,-6,1) B(3,1,2) dan C(8,5,1) jika AB wakil dari u dan BC wakil dari v.Hitunglah u.v jawab dan caranya

A(0 , -6 , 1)
B(3 , 1 , 2)
C(8 , 5 , 1)

u = AB = B - A
= (3 , 1 , 2) - (0 , -6 , 1)
= (3-0 , 1-(-6) , 2-1)
= (3 , 1+6 , 1)
= (3 , 7 , 1)
v = BC = C - B
= (8 , 5 , 1) - (3 , 1 , 2)
= (8-3 , 5-1 , 1-2)
= (5 , 4 , -1)
u.v = (3 , 7 , 1) . (5 , 4 , -1)
= 3×5 + 7×4 + 1×(-1)
= 15 + 28 - 1
= 42