Finding the intersection points of the two lines in space

In summary, to find the point of intersection for two lines in space, set the x's and y's equal to each other and solve the system for either t or s. Then, plug the resulting values into the equations for z to confirm that they give the same value. If they do, the values for t and s represent the coordinates of the intersection point. Thank you to mr. paulfr and woopydalan for their helpful replies.
  • #1
macaulay
2
0
given the lines in space

L1 : x = 2t + 1, y = 3t + 2, z = 4t + 3
L2 : x = s + 2, y = 2s + 4, z = -4s – 1
Find the point of intersection of L1 and L2.
How do i solve this?
 
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  • #2
set the x's equal to each other and solve for either t or s, then plug into the other variables to get the coordinates
 
  • #3
Another method ....
Set the x's and y's equal to each other
2t+1 = s+2
3t+2 = 2s+4
solve the system for t and s
Plug the resulting values for t and s into
z=4t+3 and z = -4s-1
to be sure they give the same value for z
If they do not, the lines are skew
If they do, then the values for t and s give the
coordinates of the intersection point for x,y and z
 
  • #4
thank u very much mr. paulfr and woopydalan...i appreciate your replies to my question.. thank u very much =)
 
  • #5


To find the point of intersection of two lines in space, we need to solve the system of equations formed by the parametric equations of the two lines. In this case, the system of equations would be:

2t + 1 = s + 2
3t + 2 = 2s + 4
4t + 3 = -4s - 1

We can solve this system by using elimination or substitution method. Once we solve for the values of t and s, we can substitute them back into the equations of the lines to find the coordinates of the point of intersection.

Alternatively, we can also use vector equations to solve for the intersection point. We can represent each line as a vector with its direction and starting point, and then set the two vectors equal to each other. This will give us a vector equation that we can solve for the values of t and s, and then find the coordinates of the point of intersection.

In either case, it is important to check for any inconsistencies or no solutions in the system of equations, as this would indicate that the two lines do not intersect in space.
 

1. How do you find the intersection points of two lines in space?

To find the intersection points of two lines in space, you must first determine the equations of both lines. This can be done using either slope-intercept form or point-slope form. Then, set the equations equal to each other and solve for the variables. The resulting values will be the coordinates of the intersection point.

2. Is it possible for two lines in space to have more than one intersection point?

Yes, it is possible for two lines in space to have more than one intersection point. This occurs when the lines are not parallel or coincident, and they intersect at different points in space.

3. What is the significance of finding the intersection points of two lines in space?

Finding the intersection points of two lines in space can be useful in various areas of mathematics and science. It can help determine the solution to a system of equations, the location of objects in space, and the angles between lines.

4. Are there any special cases when finding the intersection points of two lines in space?

Yes, there are a few special cases to consider when finding the intersection points of two lines in space. If the lines are parallel, they will never intersect and there will be no solution. If the lines are coincident, they will have an infinite number of intersection points as they overlap each other.

5. Can you find the intersection points of two lines in space without using equations?

No, in order to find the intersection points of two lines in space, you must use equations. The equations represent the lines and setting them equal to each other allows you to solve for the coordinates of the intersection point.

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