Question

Hello. I need some help with vectores. I need to express MN via a and b (arrow above MN;a;b). Also, it is said that ABCD is parallelogram. Look at the picture below. ANY IDEAS?

Answer 1

@ash2326

Answer 2

@D_Mac2k any ideas?:/

Answer 3

vector a= AD is the same length and direction as BC
that is, BC also equals a
It looks like BM is 3/5 of BC: BM= (3/5)a

similarly, vector b= DC which (because we have a parallelogram, and opposite sides are equal) = AB
b= AB
also, NB= 1/2 of AB, so NB= (1/2) b

Notice that if we start at M and go to B, then from B to N, we can write this as
MB + BN = MN

MB is BM going in the opposite direction: MB= -BM, or MB= (-3/5) a
BN is NB going in the opposite direction: BN= - NB= (-1/2) b

Answer 4

so the answer is -o,5b-0,6a?

Answer 5

yes

Answer 6

Thank you a lot! I have never understood vectores:/

Answer 7

maybe this will help
http://www.khanacademy.org/math/linear-algebra/vectors_and_spaces/vectors/v/linear-algebra--introduction-to-vectors

Answer 8

omg! Thank you so much!