Question:
Let $\vec{\alpha}=(\lambda-2) \vec{a}+\vec{b}$ and $\vec{\beta}=(4 \lambda-2) \vec{a}+3 \vec{b} \quad$ be
two given vectors where vectors $\vec{a}$ and $\vec{b}$ are non-collinear. The value of $\lambda$ for which vectors $\vec{\alpha}$ and $\vec{\beta}$ are collinear, is :
Correct Option: , 4
Solution:
$\vec{\alpha}=(\lambda-2) \vec{\alpha}+\vec{b}$
$\vec{\beta}=(4 \lambda-2) \vec{\alpha}+3 \vec{b}$
$\frac{\lambda-2}{4 \lambda-2}=\frac{1}{3}$
$3 \lambda-6=4 \lambda-2$
$\lambda=-4$
$\therefore$ Option