Question

find the magnitude and component form of the vector
3AB
3(2,-1)(3,1) I know the magnitude is the 3sqrt of 5 but i dont know how to get the component form

Answer 1

a,b are what?
co-rdinates? of what?

Answer 2

The component form of the vector is the difference between the x and y coordinates, respectively. So in your case it is (3 - 2) for x and (1 - -1) for y, which gives (1, 4).

The length of this vector can be calculated using Pythagora's theorem, and results in sqrt(5). And, finally, three times this is 3 sqrt(5).