Question

For what value of '$a$' the vectors $2\hat{i}-3\hat{j}+4\hat{k}$ and $a\hat{i}+6\hat{j}-8\hat{k}$ are collinear

Answer 1

If the vector are collinear then

$\frac{2}{a}=\frac{-3}{6}=\frac{4}{-8}=\frac{-1}{2}$

$\therefore a=-4$.