Hi,

Is there an easy way to remember the order of the vectors when doing vector subtraction? I struggle to remember from which tip you should go etc.

Thanks in advance!

/mrtester

Hi!

Since addition is a bit easier than subtraction, my way of remembering this is based on addition. To summarize your question, assume you have the following situation:

Now is $\vc{c}$ equal to $\vc{a}-\vc{b}$ or to $\vc{b}-\vc{a}$? I can never remember. So I use addition:

Clearly, if we go from the lower left point and follow $\vc{a}$ and then $\vc{c}$ we arrive at $\vc{b}$. Hence,

\begin{equation}

\vc{a} + \vc{c} = \vc{b}.

\end{equation} Now if we move $\vc{a}$ to the other side we get

\begin{equation}

\vc{c} = \vc{b} – \vc{a},

\end{equation} and we have the answer without having to memorize tip points and tail points.

Hope this works for you too!

Best Regards,

-Jacob

Thanks for the answer, I have closed the question.