Question
Show that the vectors $2\hat{i}-3\hat{j}+4\hat{k}\ \text{and}\ -4\hat{i}+6\hat{j}-8\hat{k}$ are collinear.

Answer

$\text{Let}\ \vec{a}=2\hat{i}-3\hat{j}+4\hat{k}\ \text{and}\ \vec{b}=-4\hat{i}+6\hat{j}-8\hat{k}.$
It is observed that $ \vec{b}=-4\hat{i}+6\hat{j}-8\hat{k}=-2\Big(2\hat{i}-3\hat{j}+4\hat{k}\Big)=-2\vec{a}$
$\therefore\vec{b}=\lambda\vec{a}$
where,
$\lambda=-2$
Hence, the given vectors are collinear.

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free