# Thread: Parametric Equation - method question

1. ## Parametric Equation - method question

just to check really (this isn't the actual question, just an example of the type)

Find the parametric equation of a line that passes through the points:
A = (1, 2, 3, 4), B = (3, 4, 5, 7)

Would i do: AB = (2, 2, 2, 3)

So the answer would then be:
w = 1 + 2t
x = 2 + 2t
y = 3 + 2t
z = 4 + 3t

have i done this correctly?
I was also curious how it would even be possible to have 4 points, i didnt think it was possible to think of anything more than 3 points? (3 dimensions)

Thanks

2. It looks good.
When t=0 you're at A and when t=1, you're at B.
This is linear and it is in $\displaystyle R^4$

3. Thankyou

4. Originally Posted by AshleyT
just to check really (this isn't the actual question, just an example of the type)

Find the parametric equation of a line that passes through the points:
A = (1, 2, 3, 4), B = (3, 4, 5, 7)

Would i do: AB = (2, 2, 2, 3)

So the answer would then be:
w = 1 + 2t
x = 2 + 2t
y = 3 + 2t
z = 4 + 3t

have i done this correctly?
I was also curious how it would even be possible to have 4 points, i didnt think it was possible to think of anything more than 3 points? (3 dimensions)

Thanks
First, you don't mean four points, you mean four components for one point. Yes, in 3 dimensions, a point is determined by 3 components (that's why it's called 3 dimensions). The fact that this problem gives four components for each point, instead of three, means you are working in four dimensions, not three dimensions.

5. Originally Posted by HallsofIvy
First, you don't mean four points, you mean four components for one point. Yes, in 3 dimensions, a point is determined by 3 components (that's why it's called 3 dimensions). The fact that this problem gives four components for each point, instead of three, means you are working in four dimensions, not three dimensions.
Yea...that's why i was curious...I didn't think 4 dimensions were possible, or thought of, so was wondering why they would include them in any type of maths question.