#11: History hidden
by
(deleted user)
·
2023-09-20T07:11:22Z (over 1 year ago)
Detailed history before this event is hidden because of a redaction.
Solely by eye, how can 16 year olds visually distinguish $\color{red}{\vec{b} - \vec{r}}$ from $\color{limegreen}{|\vec{b}| - |\vec{r}|}$ ?
Yearly, I teach 16 year olds the diagram beneath (improvement of [this original](https://math.stackexchange.com/a/774233)) that reappears on standardized tests _**with different letters, orientation, position of the vectors**_. Tests require students to distinguish and label $\color{red}{\vec{b} - \vec{r}}$ _vs._ $\color{limegreen}{|\vec{b}| - |\vec{r}|}$. Despite my best endeavors, someone ALWAYS mixes them red and green, whenever this diagram resurfaces on tests!
#### How do you best explain their pictoric difference? How would you prevent this diagrammatic mix up BY EYE?
