Jawaban 1721130057 Muhammad Yusuf Habibie
1. Hasil perkalian dot :
i.i = j.j = k.k = 1
= A.B = (2i + 3j + 5k).(4i + 2j - k)
= ( 2i.4i + 2i.2j - 2i.k + 3j.4i + 3j.2j - 3j.k + 5k.4i + 5k.2j
– 5k.k )
= ( 8 + 0 - 0 + 0 + 6 - 0 + 0 + 0 – 5)
= (8 + 6 - 5)
= 9
Hasil perkalian
silang :
i X i = j X j = k X k = 1
i X j = k j X i =
-k
j X k = i k X j =
-i
k X i = j k X i =
-j
= A X B = (2i + 3j +
5k) X (4i + 2j - k)
= ( (2.4)i X i + (2.2)i X j - (2.1)i X k + (3.4)j X i +
(3.2)j X j - (3.1)j X k + (5.4)k X i + (5.2)k X j – (5.1)k X k )
= 8.(0) + 4k + 2j – 12k – 6.(0) – 3i + 20j – 10i – 9.(0)
= + 4k – 12k + 2j + 20j – 3i – 10i
= – 13i + 22j – 8k
