Question

If $\overline{\alpha }$ lies in the plane of $\overline{p}$ and $\overline{q}$, then

• A. $\overline{\alpha }\cdot (\overline{p}\times \overline{q})=0$
• B. $\overline{\alpha }\cdot \overline{p}\times \overline{q}=1$
• C. $\overline{\alpha }\cdot \overline{p}\times \overline{q}=-1$
• D. $\overline{\alpha }\cdot \overline{p}\times \overline{q}=3$

Answer 1

Answer: (A)

$\overline{\alpha }\cdot (\overline{p}\times \overline{q})=0$

Since $\overline{\alpha }$ lies in the plane of $\overline{p}$ and $\overline{q}$, thus $\overline{p}$ and $\overline{q}$ are coplaner
Angle between both plane is zero
therefore option $A$