If a = (1, , , - 1) and b = ( - ,2, ,m) are two collinear vectors… - Vidyadip

MCQ

If $a = (1,\,\, - 1)$ and $b = ( - \,2,\,m)$ are two collinear vectors, then $m =$

A
$4$
B
$3$
✓
$2$
D
$0$

✓

Answer

Correct option: C.

$2$

c
(c) Condition for collinearity, $b = \lambda a$

$ \Rightarrow ( - 2i + mj) = \lambda (i - j)$

Comparison of coefficient, we get

$ \Rightarrow \lambda = - 2$ and $ - \lambda = m.$ So, $m = 2$.

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