Hard Vector Question

theBranicAc

Can anyone help me solve this vector question?

Attachment not found

The question it asks is ' Show that AMD is a straight line'

IMG_4921[1].jpg371.8KB

Reply 1

SalazarSlytherin

An angle/vertex and two mid points arent a straight line. What does the question actually say

Reply 2

TheConfusedMedic

this is my working (haven't checked it so there may be mistakes)
If you can't read anything just tell me aha I'm not used to using a laptop to draw :biggrin:

@theBranicAc

Reply 3

theBranicAc

Original post by SalazarSlytherin

An angle/vertex and two mid points arent a straight line. What does the question actually say

that is what the question says

Reply 4

theBranicAc

Original post by surina16

this is my working (haven't checked it so there may be mistakes)
If you can't read anything just tell me aha I'm not used to using a laptop to draw :biggrin:

@theBranicAc

im sorry but I can't understand it

Reply 5

TheConfusedMedic

Original post by theBranicAc

im sorry but I can't understand it

which parts? all of it?

Reply 6

theBranicAc

Original post by surina16

which parts? all of it?

all of it

Reply 7

theBranicAc

how did you get AM equals -a

Reply 8

TheConfusedMedic

Original post by theBranicAc

how did you get AM equals -a

AM = AE + EM

AE = -2a - 3b
EM = 1/2 of -EB (negative because you're going in the opposite direction
EM = 1/2 -(-a - 3b) = 1/2(a+3b)

AM = -2a -3b + 1/2a + 3/2b
AM = -1.5a - 1.5b

Reply 9

Big Moisty

Original post by theBranicAc

Can anyone help me solve this vector question?

Attachment not found

The question it asks is ' Show that AMD is a straight line'

Show AMD is a straight line by showing they're multiples of each other

Reply 10

lololololol239

-BE = -a -3b

--ME = 1/2 (-a-3b)

--AM = -3b -2a + 1/2 (a + 3b)

AM = -3b -2a + 1/2a + 3/2b

AM = -3/2b -3/2a

AM = -3/2 (b + a)

--AD = -2a -2b

AD = -2(a + b) Therefore, A, M, D are on a straight line because they have the same multiply.

I Hope This Helped. Just follow the signs. If you go the opposite way to the direction of the arrow then it is negative. You need to write a sentence using the keywords 'same multiply'. And make sure to factorise for example I did -3/2b -3/2a would be -3/2 (b + a), because -3/2 is common. We know that it is a parallelogram so the sides will e equal. I got 3b because CD + DE is the same as 2b + b which adds up to 3b. If you don't understand, try maths genie or watch a video on youtube. I wish you the best of luck.

(edited 3 years ago)

Reply 11

lololololol239

Original post by lololololol239

that is wrong.

--BE = -a -3b

--ME = 1/2 (-a-3b)

--AM = -3b -2a + 1/2 (a + 3b)
AM = -3b -2a + 1/2a + 3/2b
AM = -3/2b -3/2a
AM = -3/2 (b + a)

--AD = -2a -2b
AD = -2(a + b) Therefore, A,M, D are on a straight line because they have the same multiply.
I Hope This Helped. Just follow the signs. If you go the opposite way to the direction of the arrow then it is a negative. You need to write a sentence using the key words 'same multiply'. And make sure to factorise for example i did -3/2b -3/2a would be -3/2 (b + a), because -3/2 is common. We know that it is a parallelogram so the sides will e equal. I got 3b because CD + DE is the same as 2b + b which is adds up to 3b. If you don't understand, try maths genie or watch a video on youtube. I wish you the best of luck.