If a = 2i + 2j - k and |x ,a| , , = 1, then x = - Vidyadip

MCQ

If $a = 2i + 2j - k$ and $|x\,a|\,\, = 1,$ then $ x =$

✓
$ \pm \frac{1}{3}$
B
$ \pm \frac{1}{4}$
C
$ \pm \frac{1}{5}$
D
$ \pm \frac{1}{6}$

✓

Answer

Correct option: A.

$ \pm \frac{1}{3}$

a
(a) $|xa| = |x||a| \Rightarrow |x|\sqrt {4 + 4 + 1} = 1$$ \Rightarrow x = \pm \frac{1}{3}.$

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