Hi, just wanted to clarify my working was correct, even though I am getting a different answer from the back of the text book.

Q: Find parametric equations and

equation in vector form for the line y= 3x-1

My attempt:

Substituting x=1 and x=0 in the above equation we get two points P(1,2) and Q(0,-1) on the line

Direction vector

**d= q-p = **[-1,-3]

Vector equation is of the form

**x= p + d**t

So

**x = **[1,2] + t [-1,-3] <-----------Question: Could I factor out the -1 as the scalar quantity t covers -1?

Parametric eqn:

x= 1 + t

y= 2 + 3t

The textbook has the co-ordinates of point P and Q switched around.

Am I correct in thinking that the points are arbitrary and should not affect the equations?

Hope this makes sense.

Thanks!

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