1. ## vectors

i have been trying to do this question for quite a while now and i dont understand it...
any help would be appreciated...thanks

2. Originally Posted by b00yeah05

i have been trying to do this question for quite a while now and i dont understand it...
any help would be appreciated...thanks
Where exactly are your troubles in this question, sport? Perhaps getting started? Then:

EF = EC + CF = 1/2 AC + 1/2 CB = 1/2 (AC + CB) = 1/2 AB.

Similarly, FD = 1/2 CA.

DE = DF + FE = -1/2 CA - 1/2 AB = -1/2 (CA + AB) = -1/2 CB.

3. ive already done that part...sorry should have mentioned it. i do not know how to show that the sides are parallel for eg..how would i show that EF is parallel to AB. and i also know that the medial triangle is similar to ABC as its upside down in the centre..i just dont know how to write it down on paper or rather explain it...medial triangle is 1/2 BC which is the base.. 1/2 AC which is DF and 1/2 AB which is EF...would i just say they are parallel or the same as big triangle because they are half the length and are factors or the original triangle?

4. Originally Posted by b00yeah05
ive already done that part...sorry should have mentioned it. i do not know how to show that the sides are parallel for eg..how would i show that EF is parallel to AB. Mr F says: It's already been shown that EF = 1/2 AB, that is, EF is a scalar multiple of AB ......!

and i also know that the medial triangle is similar to ABC as its upside down in the centre..i just dont know how to write it down on paper or rather explain it...medial triangle is 1/2 BC which is the base.. 1/2 AC which is DF and 1/2 AB which is EF...would i just say they are parallel or the same as big triangle because they are half the length and are factors or the original triangle? Mr F says: You need to use the given definition and the results thus far established ....
..