Given that OA = 2i + 3j and OB = 3i — 2j, find the magnitude of AB to one decimal place.

Answer 1

a•b = 0, so OA⊥OB
Just use the Pythagorean theorem. AB = √26

Answer 2

Or, since you are showing that you work with vectors ....

vector AB = vector AO + vector OB
= <-2,-3> + <3,-2> = <1,-5>
|<1,-5>| = √26 = appr 5.1