$A$ unit vector perpendicular to vector $c$ and coplanar with vectors $a$ and $b$ is

For any three vectors $a, b, c$,the condition $a \times (b \times c) = (a \times b) \times c$ holds if:

If $\vec{a} = 2\hat{i} + \hat{j} + \hat{k}$,$\vec{b} = \hat{i} + 2\hat{j} + 2\hat{k}$,$\vec{c} = \hat{i} + \hat{j} + 2\hat{k}$ and $(1 + \alpha)\hat{i} + \beta(1 + \alpha)\hat{j} + \gamma(1 + \alpha)(1 + \beta)\hat{k} = \vec{a} \times (\vec{b} \times \vec{c})$,then $\alpha, \beta, \gamma$ are

Let $\bar{a}, \bar{b}$ and $\bar{c}$ be three vectors having magnitudes $1, 1$ and $2$ respectively. If $\bar{a} \times(\bar{a} \times \bar{c})+\bar{b}=\bar{0}$,then the acute angle between $\bar{a}$ and $\bar{c}$ is

If $(\bar{a} \times \bar{b}) \times \bar{c} = -5 \bar{a} + 4 \bar{b}$ and $\bar{a} \cdot \bar{b} = 3$,then the value of $\bar{a} \times (\bar{b} \times \bar{c})$ is

Let $\vec{x}, \vec{y}$ and $\vec{z}$ be three vectors each of magnitude $\sqrt{2}$ and the angle between each pair of them is $\frac{\pi}{3}$. If $\vec{a}$ is a nonzero vector perpendicular to $\vec{x}$ and $\vec{y} \times \vec{z}$ and $\vec{b}$ is a nonzero vector perpendicular to $\vec{y}$ and $\vec{z} \times \vec{x}$,then
$(A)$ $\vec{b}=(\vec{b} \cdot \vec{z})(\vec{z}-\vec{x})$
$(B)$ $\vec{a}=(\vec{a} \cdot \vec{y})(\vec{y}-\vec{z})$
$(C)$ $\vec{a} \cdot \vec{b}=-(\vec{a} \cdot \vec{y})(\vec{b} \cdot \vec{z})$
$(D)$ $\vec{a}=(\vec{a} \cdot \vec{y})(\vec{z}-\vec{y})$