Equations of Lines/Multivariable Calculus

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Homework Help Overview

The problem involves determining the relationship between two lines in three-dimensional space, specifically whether they intersect, are skew, or are parallel. The lines are defined by their parametric equations.

Discussion Character

  • Exploratory, Mathematical reasoning

Approaches and Questions Raised

  • The original poster attempts to solve the equations for parameters s and t to find the intersection point. They express uncertainty about their method for finding the intersection and question the validity of their calculated x-coordinate.

Discussion Status

Some participants provide guidance on verifying the intersection point by substituting the parameters back into the original line equations. There is acknowledgment of the original poster's confusion regarding the x-coordinate, but no consensus on the final outcome is reached.

Contextual Notes

The original poster mentions a specific value for the x-coordinate of the intersection, which raises questions about their calculations. There is an implication of needing to double-check the math involved in finding the intersection.

EngnrMatt
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Homework Statement



Determine whether the lines
L1:x=t, y=16+4t ,z=8+t
and
L2:x=−7+2t, y=−8+6t, z=−3+4t
intersect, are skew, or are parallel. If they intersect, determine the point of intersection

Homework Equations



t = -7 + 2s

16 + 4t = -8 + 6s

8 + t = -3 + 4s

The Attempt at a Solution



I solved the first two equations for s and t then plugged them into the third which confirmed that the lines intersect. To determine the point of intersection, I figured that setting the parametric equations equal to each other and solving for t would give the correct answer, but that doesn't seem to be the right way (I got 7 for the x-coordinate of the intersection).

So my question is how do I find the intersection?
 
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Once you found out that the lines interesected by solving for t and s, substituting either t in L1 or s in L2 would give you the point of intersection. They should match up if you do both. (And I'm not sure about 7 for the x-coordinate, double check your math).
 
Yep, you're right, thanks! It worked.
 
Sure thing!
 

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