Parametric Equations for Line PQ: Find Solution

[major_maths]

1. Find parametric equations for the line joining the points P = (1,2,-1) and Q = (5,7,5).[/b]

2. x = x₀+ta
y = y₀+tb
z = z₀+tc

3. v = <(5-1), (7-2), (5+1)>
so v = <4,5,6> and since v is a vector in the direction of the line and should be able to be placed in the above equations in place of <a,b,c> and either of the point (P or Q) should be placed in the values of x₀, y₀, and z₀. This should result in the final parametric equations:

x = 1+4t
y = 2+5t
z = -1+6t

This is a problem on one of my tests but my teacher marked it wrong, noting that "line PQ = <4,5,6> is the normal" and marked off 6 points out of 10. I've got no clue what I did wrong.

 

[Dick]

I don't see anything wrong with that.

 

[Omega_Prime]

Hm, I'm a student myself but that looks correct to me...

I would've done the same thing!