C4 vectors

hi, can anyone help me with this:

OABCDE is a regular hexagon. the points A and B have position vectors a and b respectively, referred to the origin O.
find, in terms of a and b , the position vectors of C, D and E.

Reply 1

Malik

mathsguru

Draw a hexagon label it, then look at my method pretty straight foward.

OC=2AB (Because OC is paralell to AB)
=2(b−a)
=−2a+2b

OD=OC+CD=OC+AO
=(−2a+2b)−a
=−3a+2b

OE=OD+DE=OD+BA
=(−3a+2b)+(a−b)
=−2a+b

Reply 2

Amyallaway

If you look at the national 5 specimen paper 1 non calculator, on the SQA website then you will find that question 11 is the one that mathsguru is trying to solve. Btw I also trying to solve that question and your answer has confused me.