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Mathematics
Mathematics
Problem
The vector
r
\mathbf{r}
r
satisfying the conditions that I. it is perpendicular to
3
i
^
+
2
j
^
+
2
k
^
3\hat{\mathbf{i}} + 2\hat{\mathbf{j}} + 2\hat{\mathbf{k}}
3
i
^
+
2
j
^
+
2
k
^
and
18
i
^
−
22
j
^
−
5
k
^
18\hat{\mathbf{i}} - 22\hat{\mathbf{j}} - 5\hat{\mathbf{k}}
18
i
^
−
22
j
^
−
5
k
^
II. it makes an obtuse angle with
Y
Y
Y
-axis. III.
∣
r
∣
=
14
|\mathbf{r}| = 14
∣
r
∣
=
14
a.
2
(
−
2
i
^
−
3
j
^
+
6
k
^
)
2(-2\hat{\mathbf{i}} - 3\hat{\mathbf{j}} + 6\hat{\mathbf{k}})
2
(
−
2
i
^
−
3
j
^
+
6
k
^
)
b.
2
(
2
i
^
−
3
j
^
+
6
k
^
)
2(2\hat{\mathbf{i}} - 3\hat{\mathbf{j}} + 6\hat{\mathbf{k}})
2
(
2
i
^
−
3
j
^
+
6
k
^
)
c.
4
i
^
+
6
j
^
−
12
k
^
4\hat{\mathbf{i}} + 6\hat{\mathbf{j}} - 12\hat{\mathbf{k}}
4
i
^
+
6
j
^
−
12
k
^
d. None of the above
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