Question

Dados os vetores u=(1,2,-3), v(2,1,-1) e w(3,1,1), calcule : a) u.v b) (u-v).w

Answer 1

a) u.v = (1,2,-3) * (2,1,-1) = 1*2 + 2*1 + -3* -1 = 2 + 2 + 3 = 7

b) (u-v).w = 

u-v = (1,2,-3) - (2,1,-1) = (1-2, 2-1, -3 - -1) = (-1, 1, -2)

(-1, 1, -2) . (3,1,1) = -1*3 + 1*1 + -2*1 = -3 + 1 - 2 = -4