# Thread: Spatial vectors

1. ## Spatial vectors

Let $\vec{a}$ and $\vec{a}$ be 3d vectors.

Explain in words with the aid of a diagram why:
( $\vec{a}$x $\vec{b}$). $\vec{b}$ = 0.

Explain with the aid of a diagram, that if
$\vec{b}$x( $\vec{a}$. $\vec{b}$) = $\vec{a}$,
what is $\vec{a}$. $\vec{b}$?

should be using right hand rules etc

2. ## Re: Spatial vectors

Originally Posted by whyyie
Explain in words with the aid of a diagram why:
( $\vec{a}$x $\vec{b}$). $\vec{b}$ = 0.

Explain with the aid of a diagram, that if
$\vec{b}$x( $\vec{a}$. $\vec{b}$) = $\vec{a}$,
what is $\vec{a}$. $\vec{b}$?
These should be easy to answer if you set up a diagram.

What do we know, geometrically, about the cross product of two vectors? And when will the dot product of two vectors be zero?