(7.) Diketahui vektor vec a =2 hat i +3 hat j , vec b = hat i -4 hat j ,dan vec c =4 hat j Tentukan
a. vec a + vec b
b. vec a + vec c ;
c. vec a + vec b + vec c
d. 1/2 vec c - vec a
e. 2/3 vec a + 1/2 vec b
f. vec a - 1/4 vec b + 1/4 vec c
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a. vec a + vec b
b. vec a + vec c ;
c. vec a + vec b + vec c
d. 1/2 vec c - vec a
e. 2/3 vec a + 1/2 vec b
f. vec a - 1/4 vec b + 1/4 vec c
Jawaban:
vektor
panjang vektor
__
soal
\begin{gathered}\sf \overline {d} =\overline {a} + \overline {b} - \overline {c}\sf\\\\\sf \overline {d} = \binom {3+1+3}{-2+0-4} = \binom{7}{-6}\sf\\\\\sf |\overline {d}| = \sqrt{7^2 + (-6)^2} = \sqrt{85}\end{gathered}
d
=
a
+
b
−
c
d
=(
−2+0−4
3+1+3
)=(
−6
7
)
∣
d
∣=
7
2
+(−6)
2
=
85
