# Thread: Find symetric equations for the line of intersection of the planes.

1. ## Find symetric equations for the line of intersection of the planes.

Find symmetric equations for the line of intersection of the planes.

5x - 2y - 2z = 1

4x + y + z = 6

I interpret this problem to say that I need to find a line of intersection of the two planes. I think I add them together and get 9x -y -z = 7.

After which, I need to find symmetric equations of that line and I think that is what I am having trouble with. I would like a little background into what a symmetric equation is. The book says that I need to first find a parametric equation then solve for t. Thanks!

2. Originally Posted by jdj333
Find symmetric equations for the line of intersection of the planes.

5x - 2y - 2z = 1

4x + y + z = 6

I interpret this problem to say that I need to find a line of intersection of the two planes. I think I add them together and get 9x -y -z = 7. Mr F says: This is not the equation of a line. It's the equation of a plane.

After which, I need to find symmetric equations of that line and I think that is what I am having trouble with. I would like a little background into what a symmetric equation is. The book says that I need to first find a parametric equation then solve for t. Thanks!
First get the equations of the line in parametric form by following the reply in this thread: http://www.mathhelpforum.com/math-he...-equation.html