1
$\begingroup$

Let's say I have 2 unit vector of X and Y. I have to find another vector of Z. So if I were to cross X and Y to get Z, will Z also be a unit vector?

1 Answers 1

2

We know that the magnitude of the cross product of $\vec x $ and $\vec y $ is given by: $$|\vec x \times \vec y| = |\vec x||\vec y| \sin \theta $$ where $\theta $ is the angle between the two vectors.

Now consider what will happen if $\vec x = \vec y $. Even if $\vec x \neq \vec y $, we do have, $|\vec x|=|\vec y| = 1$. Thus, $$ |\vec x \times \vec y| = \sin \theta $$

Hope you can take it from here.

  • 0
    I believe he's asking about when x and y are unit vectors, not the case that x = y. Besides the last statement, though, it does answer his question :)2017-02-08
  • 1
    @AliasUser Even if $\vec x \neq \vec y $, we do have $|\vec x| = |\vec y|=1$. Thus $|\vec x \times \vec y| = \sin \theta $. Then, $\cdots $?2017-02-08
  • 0
    Good point -- thank you!2017-02-08