Jawaban 1731130110 Yayan Rachmadianto

1. Diketahui 2 buah vektor :
A = 3i+5j-7k

B = 2j+5k
Tentukan :
AxB!

Jawab

axb = (3i + 5j-7k) . (2j + 5k) 

 =6k-15j+0+25i+14i-0

=6k-15j+39i

2. Diketahui tiga vektor berikut.

x = 2i + 3j
y = 3i + 2j
z = i + j + k

 Hitunglah

a) x . y

b) (x + y) . z

Jawab

a) x . y = (2i + 3j) . (3i + 2j)

x . y = (2)(3) + (3)(2)

x . y = 6 + 6

x . y = 12

b) x + y = (2i + 3j) + (3i + 2j)

 x + y = 5i + 5j

= (x + y) . z = (5i + 5j) . (i + j + k)

(x + y) . z = (5)(1) + (5)(1) + (0)(1)

(x + y) . z = 5 + 5 + 0

(x + y) . z = 10

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