# I am right aren't I?

Discussion in 'Mathematics' started by ResourceFinder, Mar 8, 2011.

1. ### ResourceFinder

A question in a paper I was looking at asked for the vector equation of a line through 2 given points

The mark scheme gives an answer .... not even oe

So I am right am I not .... there are infinite vector equations for the line going through 2 points

Also the difference between the 2 points was [2,4,2] so I gave the answer as
r = [vector] + t[1,2,1] whereas they still used r = [vector] + s[2,4,2] Now, I agree that theirs is one of the infinite available but I am inclined to cancel the "gradient" vector

Thing is ... it has been ages since I did vectors so I am doubting myself

2. ### ResourceFinder

A question in a paper I was looking at asked for the vector equation of a line through 2 given points

The mark scheme gives an answer .... not even oe

So I am right am I not .... there are infinite vector equations for the line going through 2 points

Also the difference between the 2 points was [2,4,2] so I gave the answer as
r = [vector] + t[1,2,1] whereas they still used r = [vector] + s[2,4,2] Now, I agree that theirs is one of the infinite available but I am inclined to cancel the "gradient" vector

Thing is ... it has been ages since I did vectors so I am doubting myself

3. ### DMNew commenter

Yes you are correct.

4. ### DMNew commenter

direction vector might be better terminology than gradient vector

Thought so