AQA Core 4 7.01 Introducing Vectors in 3D

[Dan-ghsd]

I have no idea if you need to add or subtract vectors to fine another vector any tips how to figure it out?

[BenJordy]

hey jack, really quick question, how do you know, in an exam question or otherwise, that a vector is AB or BA, I've got a question where two lines are perpendicular but I don't know how to tell which way the vectors go round??