promitheus
New member
- Joined
- Aug 19, 2017
- Messages
- 18
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 + dt
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!
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 + dt
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!