Jawaban 1731130018 Ramadhaniar Sekarsari
Jawaban :
Soal 1
Diket : A= 8i + 4j - 2kB= 4i + 3j
Ditanya : a). A x B
b). Buktikan A x B = -B x A
Jawab :
a). A x B = ( 8i + 4j - 2k) x (4i + 3j)
= (0) + (24.k) + (-16.k) + (0) - (8.j) - (-6.i)
= 24k - 16k - 8j + 6i
= 8k - 8j + 6i
= 6i - 8j + 8k
b). A x B = -B x A
6i - 8j + 8k = -(4i + 3j) x ( 8i + 4j - 2k)
= (-4i - 3j) x ( 8i + 4j - 2k)
= (0) - (16k) + (-8j) - (-24k) - (0) + (6i)
= -16k - 8j + 24k + 6i
= 8k - 8j + 6i
6i - 8j + 8k = 6i - 8j + 8k
Soal 2
Diket : A = 6i + 4jc.A = 10 satuan
Ditanya : nilai konstanta skalar c?
Jawab : A = 6i + 4j
|A| = √6² + 4²
= √36 + 16
= √52
= 2 √13
= 7,21
c.A = 10 satuan
c.7,21 = 10
c = 10
7,21
= 1,39