- #1
Argyron
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I missed 2 weeks of class where we were introduced to vectors and now I have to learn it by myself from the book. I'm stuck on this problem that's part of the assigned homework. If anyone could help me that would be great thanks.
I'm sorry if it's a stupid mistake :/
In triangle OAB, [itex]\vec{OA} = a[/itex] and [itex]\vec{OB} = b[/itex]
P is a point on AB such that [itex]\vec{AP} = 2\vec{PB}[/itex]
and Q is a point such that [itex]\vec{OP} = 3\vec{PQ}[/itex]
Express the following in terms of a and b.
a) [itex]\vec{BA}[/itex]
b) [itex]\vec{PB}[/itex]
c) [itex]\vec{OP}[/itex]
d) [itex]\vec{PQ}[/itex]
e) [itex]\vec{BQ}[/itex]
N/A
a) [itex]\vec{BA} = a-b[/itex]
b) [itex]\vec{PB} = 1/3(b-a)[/itex]
I got stuck on c)
My working out is
[itex]\vec{OP} = \vec{OB} + \vec{BP}[/itex] [Express both vectors in a and b]
[itex]\vec{OP} = b + 1/3(a-b)[/itex]
But when I check my answer the book said it was:
[itex]1/3(a+2b)[/itex]
Where did I go wrong?
I'm sorry if it's a stupid mistake :/
Homework Statement
In triangle OAB, [itex]\vec{OA} = a[/itex] and [itex]\vec{OB} = b[/itex]
P is a point on AB such that [itex]\vec{AP} = 2\vec{PB}[/itex]
and Q is a point such that [itex]\vec{OP} = 3\vec{PQ}[/itex]
Express the following in terms of a and b.
a) [itex]\vec{BA}[/itex]
b) [itex]\vec{PB}[/itex]
c) [itex]\vec{OP}[/itex]
d) [itex]\vec{PQ}[/itex]
e) [itex]\vec{BQ}[/itex]
Homework Equations
N/A
The Attempt at a Solution
a) [itex]\vec{BA} = a-b[/itex]
b) [itex]\vec{PB} = 1/3(b-a)[/itex]
I got stuck on c)
My working out is
[itex]\vec{OP} = \vec{OB} + \vec{BP}[/itex] [Express both vectors in a and b]
[itex]\vec{OP} = b + 1/3(a-b)[/itex]
But when I check my answer the book said it was:
[itex]1/3(a+2b)[/itex]
Where did I go wrong?
