Question

Dados os vetores u = (1, -2, 3) e v = (4, 2, -1) calcule

Answer 1

Resposta:

7)

1.

$u = (1, - 2,\: 3) \: e \: v(4 \: ,2, - 1) \\ \\ (u + v).(2u - v) \\ \\( (1 \:, - 2 \:, 3) + (4 \:, 2 \:, - 1).(2(1 \:, - 2 \: ,3) - (4 \:, 2 \:, - 1)) \\ \\ ((5 ,\: 0, \: 2).(2 \:, - 4 \: , \: 6) - (4 \:, 2 \: , - 1)) \\ \\ ((5 \: ,0\:, 2) .( - 2 \: , - 6 \: , \: 7)) \\ \\ - 10 + 0 + 14 \\ \\ = - 10 + 14 \\ \\ = \green{4}$

2.

$(u.u) = \\ \\ = (1 \: , - 2 \:, 3).(1 \:, - 2 \:, 3) \\ \\ = 1 +4 + 9 \\ \\ = 5 + 9 \\ \\ = \green{ 14}$

Bons Estudos!