1.If a⃗\vec{a}a makes an acute angle with b⃗\vec{b}b, r⃗⋅a⃗=0\vec{r} \cdot \vec{a} = 0r⋅a=0 and r⃗×b⃗=c⃗×b⃗\vec{r} \times \vec{b} = \vec{c} \times \vec{b}r×b=c×b, then r⃗=\vec{r} =r=a.a⃗×c⃗−b⃗\vec{a} \times \vec{c} - \vec{b}a×c−bb.c⃗×a⃗\vec{c} \times \vec{a}c×ac.c⃗−c⃗⋅a⃗b⃗⋅a⃗b⃗\vec{c} - \frac{\vec{c}\cdot\vec{a}}{\vec{b}\cdot\vec{a}} \vec{b}c−b⋅ac⋅abd.c⃗+c⃗⋅a⃗b⃗⋅a⃗b⃗\vec{c} + \frac{\vec{c}\cdot\vec{a}}{\vec{b}\cdot\vec{a}} \vec{b}c+b⋅ac⋅abLogin to continueOnly logged in users canattempt or see the solution.