1. ## vector problem

could someone tell me of this answer is correct:
the triangle ABC has verticies A(-1,3,0), B(-3,0,7), C(-1,2,3). Find a) AB

A: 21i+10j-9k ?

cheers.

2. Originally Posted by hyzlemon
could someone tell me of this answer is correct:
the triangle ABC has verticies A(-1,3,0), B(-3,0,7), C(-1,2,3). Find a) AB

A: 21i+10j-9k ?

cheers.
No, that's completely wrong! "AB" is NOT a multiplication- you do not "multiply" points- it is the vector from A to B: (-3-(-1))i+ (0- 3)j+ (7- 0)k.

3. ok thanks, that was actually my original answer but i was told that it was wrong for some reason, by a phd student aswell.