5. Jika A = (2, -1) dan B = (-3, 4), tentukan hasil A.B!
Jawaban: A.B = (2*-3) + (-1*4) = -6 – 4 = -10
6. Tentukan vektor yang tegak lurus dengan vektor A = (1, 1)!
Jawaban: B = (-1, 1) atau B = (1, -1)
7. Tentukan hasil proyeksi vektor B = (3, 4) terhadap vektor A = (1, 1)!
Jawaban: B.projeksi.A = (B.A/|A|2) * A = ((3*1) + (4*1))/(1^2 + 1^2) * (1, 1) = (7/2) * (1, 1) = (7/2, 7/2)
