# help!! maths hwk

i haven't got really far with this question, but i've got the mark scheme and it says --BA--> = a - 3b?
is this just a rule that one side - another side = to the other side of the triangle? or related to pythagoras in some way?
(edited 4 months ago)
Original post by august_gilmore
i haven't got really far with this question, but i've got the mark scheme and it says --BA--> = a - 3b?
is this just a rule that one side - another side = to the other side of the triangle? or related to pythagoras in some way?

BA = BO + OA = -OB + OA = -3b + a
its just the usual vector tip to tail addition. Tbh, Id try not to look at the mark scheme and think about what you need to do to solve the problem.
(edited 4 months ago)
Original post by mqb2766
BA = BO + OA = -OB + OA = -3b + a
its just the usual vector tip to tail addition. Tbh, Id try not to look at the mark scheme and think about what you need to do to solve the problem.

thank you!
im about to do my mocks and i was doing a past paper for practice and realised its not going to be on the mock lol bc we havent learn it. anyways, thanks!!