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Mathematics
Mathematics
Problem
With
a
=
(
1
,
−
1
,
2
)
\mathbf a=(1,-1,2)
a
=
(
1
,
−
1
,
2
)
and
b
=
(
2
,
0
,
−
1
)
\mathbf b=(2,0,-1)
b
=
(
2
,
0
,
−
1
)
, evaluate
(
2
a
−
b
)
×
(
a
+
3
b
)
(2\mathbf a-\mathbf b)\times(\mathbf a+3\mathbf b)
(
2
a
−
b
)
×
(
a
+
3
b
)
. The result is a)
7
i
^
−
35
j
^
+
14
k
^
7\hat{i}-35\hat{j}+14\hat{k}
7
i
^
−
35
j
^
+
14
k
^
b)
7
i
^
+
35
j
^
+
14
k
^
7\hat{i}+35\hat{j}+14\hat{k}
7
i
^
+
35
j
^
+
14
k
^
c)
−
7
i
^
−
35
j
^
−
14
k
^
-7\hat{i}-35\hat{j}-14\hat{k}
−
7
i
^
−
35
j
^
−
14
k
^
d)
5
i
^
+
25
j
^
+
10
k
^
5\hat{i}+25\hat{j}+10\hat{k}
5
i
^
+
25
j
^
+
10
k
^
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