Mathematics - Vector Question with Solution | TestHub

Given $\vec{a},\vec{b},\vec{c}$ are vectors such that $\vec{b}$ and $\vec{c}$ are unit, like and parallel vectors and $|\vec{a}|=4$. If $\vec{a}+\lambda \vec{c}=2\vec{b}$, find the sum of all possible values of $\lambda$.