Answer
a) $\vec {AC}$
b) $\vec {CB}$
c) $\vec {DA}$
d) $\vec {DB}$
Work Step by Step
The vector sum $\vec {AB} + \vec {BC}$ will be the vector that connects the initial point of $\vec {AB}$, which is $A$, to the terminal point of $ \vec {BC}$, which is C. Therefore $ \vec {AB} + \vec {BC}$ = $ \vec {AC}$.
The vector sums b) and d) are carried out in the same way.
For c), we first change the direction of the second vector to convert the vector subtraction into a vector sum. We then have:
$ \vec {DB}$ – $ \vec {AB} = \vec {DB}$+ $ \vec {BA}$
This vector sum will be the vector going from D to A, namely $\vec {DA}$.
