Razlika vektorjev $\overset{\rightharpoonup}{a}-\overset{\rightharpoonup}{b}$ je vektor, ki ga moramo prišteti vektorju $\overset{\rightharpoonup}{b}$, da dobimo vektor $\overset{\rightharpoonup}{a}$. Velja:
$$\overset{\rightharpoonup}{a}-\overset{\rightharpoonup}{b}=\overset{\rightharpoonup}{c}\iff \overset{\rightharpoonup}{b}+\overset{\rightharpoonup}{c}=\overset{\rightharpoonup}{a}$$
Na sliki sta narisana vektorja $\overset{\rightharpoonup}{a}$ in $\overset{\rightharpoonup}{b}$. Preriši ju v zvezek in nariši vektorja $\overset{\rightharpoonup}{a}-\overset{\rightharpoonup}{b}$ in $\overset{\rightharpoonup}{a}+(-\overset{\rightharpoonup}{b})$. Kaj opaziš? Pomagaj si s premiki drsnika in preveri svoja opažanja.
Razliko $\overset{\rightharpoonup}{a}-\overset{\rightharpoonup}{b}$ narišemo tudi tako, da vektorju $\overset{\rightharpoonup}{a}$ prištejemo nasprotni vektor vektorja $\overset{\rightharpoonup}{b}$:
$$\overset{\rightharpoonup}{a}-\overset{\rightharpoonup}{b}=\overset{\rightharpoonup}{a}+(-\overset{\rightharpoonup}{b})$$
Poenostavi:
a) $\overset{\Large\rightharpoonup}{AB}-\overset{\Large\rightharpoonup}{AD}$ b) $\overset{\Large\rightharpoonup}{AD}-\overset{\Large\rightharpoonup}{BC}$ c) $\overset{\Large\rightharpoonup}{CA}-\overset{\Large\rightharpoonup}{DA}$
Svoje izbire utemelji.