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Mathematics
Mathematics
Problem
If vector
i
^
+
2
j
^
+
2
k
^
\hat{i} + 2\hat{j} + 2\hat{k}
i
^
+
2
j
^
+
2
k
^
is rotated through an angle of
90
∘
90^\circ
9
0
∘
, so as to cross the positive direction of
Y
Y
Y
-axis, then the vector in the new position is a.
−
2
5
i
^
+
5
j
^
−
4
5
k
^
-\frac{2}{\sqrt{5}}\hat{i} + \sqrt{5}\hat{j} - \frac{4}{\sqrt{5}}\hat{k}
−
5
2
i
^
+
5
j
^
−
5
4
k
^
b.
2
5
i
^
−
5
j
^
+
4
5
k
^
\frac{2}{\sqrt{5}}\hat{i} - \sqrt{5}\hat{j} + \frac{4}{\sqrt{5}}\hat{k}
5
2
i
^
−
5
j
^
+
5
4
k
^
c.
4
i
^
−
j
^
−
k
^
4\hat{i} - \hat{j} - \hat{k}
4
i
^
−
j
^
−
k
^
d. None of these
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