Answer:
The displacement vector is [tex]-0.59 \hat i -0.82 \hat j[/tex]
Explanation:
Taking East as positive x-axis having a unit vector [tex]\hat i[/tex] and North as positive y-axis having a unit vector [tex]\hat j[/tex].
So, west and south are in negative x and negative y directions respectively.
As she walks 0.40 miles south, 0.65 miles east, 0.78 miles north, 1.24 miles west then 1.20 miles south.
Scaling 1 mile as 1 unit vector, so 1 mile east = 1 [tex]\hat i[/tex] and so on
Adding all the displacement vectors, we have
[tex]\vec {v} = -0.40 \hat j +0.65 \hat i + 0.78 \hat j -1.24 \hat i - 1.20 \hat j[/tex]
[tex]\vec {v} = -0.59 \hat i -0.82 \hat j[/tex]
Hence, the displacement vector is [tex]-0.59 \hat i -0.82 \hat j[/tex]