Can the Intersection of Two Lines Prove the Existence of a Plane?

In summary, the conversation discusses the concept of a plane in classical mathematics and its use as a proof. It is mentioned that in classical mathematics, the plane is taught as an axiom and there are definitions for planes. The conversation also explores the idea of multiple lines intersecting at a single point and potentially forming a plane. The concept of a Cartesian coordinate system and its relation to planes is also brought up. Finally, it is mentioned that two intersecting lines can define a unique plane by using the cross product of their direction vectors.
  • #1
point
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in classical mathematics plane is taught as an axiom, I question whether the plane can be a proof, let's start from the assumption that there are [tex]n ( n>1)[/tex] line that intersect at a single point in space , from them can be proved that the plane can be used as evidence, ..
 
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  • #2
point said:
in classical mathematics plane is taught as an axiom, I question whether the plane can be a proof, let's start from the assumption that there are [tex]n ( n>1)[/tex] line that intersect at a single point in space , from them can be proved that the plane can be used as evidence, ..
You can have multiple lines that all intersect at the same point but which are not in the same plane unless of course you want to first posit the existence of a plane and then say that all the lines have to be in that plane and thus they prove that the plane exists but first you would have to posit that that plane exists and then ...
 
  • #3
point said:
in classical mathematics plane is taught as an axiom,
There are definitions for planes, but maybe that's what you mean.
point said:
I question whether the plane can be a proof,
?
What does this mean? One definition (from Wikipedia) is that a plane "is a flat, two-dimensional surface."
point said:
let's start from the assumption that there are [tex]n ( n>1)[/tex] line that intersect at a single point in space , from them can be proved that the plane can be used as evidence, ..
The plane can be used as evidence for what?
As @phinds has already said, you can have multiple (i.e., more than two) lines that intersect at a common point without the lines determining a plane.

Where are you trying to go with this?
 
  • #4
phinds said:
You can have multiple lines that all intersect at the same point but which are not in the same plane unless of course you want to first posit the existence of a plane and then say that all the lines have to be in that plane and thus they prove that the plane exists but first you would have to posit that that plane exists and then ...
2-plane
aaa.png

1. two line intersect at point A , space
2. AB=AC=AD=AE
3. straight lines DB , BE , CE , CD
The first process - point B slides on the line to point A , straight lines DB (BE , CE , CD ) intersecting space , formed a final surface BDCE
Second process - point B slides on the line moving away from point A , straight lines DB (BE , CE , CD ) intersecting space , formed infinitive surface

Merging the surface, we get what we now know plane

how to get out of this function plane ? , because the Cartesian coordinate system is constant
 
  • #5
I have no idea what you are talking about. Yes, your figure makes sense. You have some lines in a plane. So what? What is your point? What is your question?
 
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  • #6
It is true that two intersecting lines define a unique plane. Take the cross product of vectors in the directions of the lines, then use that as normal vector to the plane.

For example, the two lines x= 3t+ 2, y= 2t- 4, z= t+ 1 and x= t, y= -t- 2, z= t- 1 intersect at (2, -4, 1) (with t= 0 for the first line, t= 2 for the second). A vector in the direction of the first line is <3, 2, 1> and a vector in the direction of the second line is <1, -1, 1>. The cross product of those two vectors is <3, -2, -5>. The plane having that normal vector and containing the point (2, -4, 1) is 3(x- 2)- 2(y+ 4)- 5(z- 1)= 0.
 

1. What is a plane of evidence?

A plane of evidence refers to a method used in scientific research to gather and analyze data. It involves organizing data into categories or levels, which can then be used to draw conclusions and support scientific theories.

2. How is a plane of evidence used in scientific research?

In scientific research, a plane of evidence is used to gather and organize data in a systematic and objective way. It helps researchers to identify patterns, make predictions, and draw conclusions based on the evidence collected.

3. What are the different levels or categories used in a plane of evidence?

The levels or categories used in a plane of evidence can vary depending on the specific research being conducted. However, some common categories include observations, experiments, surveys, and statistical analyses.

4. What are the advantages of using a plane of evidence in scientific research?

Using a plane of evidence in scientific research allows for a structured and systematic approach to data collection and analysis. It helps to minimize bias and ensures that conclusions are based on strong evidence.

5. Are there any limitations to using a plane of evidence in scientific research?

While a plane of evidence can be a useful tool in scientific research, it is important to note that it does have some limitations. For example, it may not be suitable for all types of research, and it may not account for all variables or factors that could affect the data being collected.

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