# vectors help.

• April 25th 2010, 03:26 AM
Tweety
vectors help.
Given that;

$XY = \begin{pmatrix} 2\\ 4 \\ 6 \end{pmatrix}$

$ZX = \begin{pmatrix} -10 \\ -8 \\ 6 \end{pmatrix}$

find YZ.

I am not sure how to work this out, and my textbook does not show me an example, can someone please show me?

Thanks.
• April 25th 2010, 07:03 AM
Failure
Quote:

Originally Posted by Tweety
Given that;

$XY = \begin{pmatrix} 2\\ 4 \\ 6 \end{pmatrix}$

$ZX = \begin{pmatrix} -10 \\ -8 \\ 6 \end{pmatrix}$

find YZ.

I am not sure how to work this out, and my textbook does not show me an example, can someone please show me?

Thanks.

Make a drawing that shows the points X, Y, and Z. Then try to traverse that triangle from Y to Z along edges that you know how to express in terms of the given vectors:

$\vec{YZ} = \vec{YX}+\vec{XZ}=-\vec{XY}-\vec{ZX}=-\begin{pmatrix}2\\4\\6\end{pmatrix}-\begin{pmatrix}-10\\-8\\6\end{pmatrix}=\ldots$