Question

This is the given information:

A student bikes to school by traveling first dN = 1.10miles north, then dW = 0.400miles west, and finally dS = 0.100miles south.

part a asked:
If a bird were to start out from the origin (where the student starts) and fly directly (in a straight line) to the school, what distance db would the bird cover?

the answer i got to this was 1.08 miles and it was correct, i used the Pythagorean theorem

Im stuck on part B, it asked

You will now find the same quantity algebraically, without the need to use much geometry. Take the north direction as the positive y direction and east as positive x. The origin is still where the student starts biking.
Let d⃗ N be the displacement vector corresponding to the first leg of the student's trip. Express d⃗ N in component form.

Answer 1

I think they just want you to add the squares of the components and then take the square root of that sum, which seems what you did in (a).

Answer 2

ok thank you i think i got it