Solve Coordinate Geometry Problem: Find Line Equation

  • Thread starter Thread starter Reshma
  • Start date Start date
  • Tags Tags
    Line
Join the discussion
Ask a follow-up here, or get your own question answered by working scientists, mathematicians and engineers — people, not an autocomplete.
Real named experts · corrections over time · the nuance an AI answer skips
1 reply · 3K views
Reshma
Messages
749
Reaction score
6
I think my coordinate geometry skills have turned rather rusty. :frown:
Just help me out with this problem.

Find the symmetric and parametric equation of a line passing through (3, 4, -1) and parallel to 2i - 3j + 6k.

Here is my attempt at this:

Since the line passes through (3,4,-1) the equation would be given by:
(x - 3) + (y - 4) + (z +1) = 0

But, this looks like the equation of a plane :bugeye: . I am all confused now. How do I relate this line to the vector parallel to it?
 
Physics news on Phys.org
Yes, that's the equation of the plane through (3, 4, -1) and perpendicular to 2i- 3j+ 6k. You can't write a line in 3 dimensions in just one equation. Write it in parametric equations:
x= x0+ at, y= y0+ bt, z= z0+ ct where (x0, y0, z0) is a point on the line and ai+ bj+ ck is a vector in the direction of the line.