Sketching a simple plane in R3 (should be easy, but not for me :P)

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    Plane
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Discussion Overview

The discussion revolves around the process of sketching a plane in three-dimensional space (R3) based on the equation 5y - z - 10 = 0. Participants explore the identification of intercepts and the visualization of the plane, addressing challenges in representing three-dimensional concepts on two-dimensional media.

Discussion Character

  • Exploratory, Conceptual clarification, Technical explanation

Main Points Raised

  • One participant identifies the y-intercept as 2 and the z-intercept as -10, noting the absence of an x-term suggests the plane is parallel to the x-axis.
  • Another participant expresses confusion about how to draw a rectangular section of the plane that is parallel to the x-axis, describing their initial sketch as skewed.
  • A participant suggests drawing the line 5y - z = 10 in the yz-plane and visualizing it being lifted to form the plane.
  • One participant introduces the concept of a normal vector associated with the plane's equation, indicating that understanding this can help in visualizing the plane's orientation.
  • A later reply indicates a realization that the initial approach to sketching may have been incorrect, acknowledging the difficulty of representing three-dimensional objects on two-dimensional paper.

Areas of Agreement / Disagreement

Participants express varying levels of understanding and visualization techniques, with no consensus on a single method for sketching the plane. The discussion remains exploratory, with multiple approaches being considered.

Contextual Notes

Participants express limitations in visualizing three-dimensional space on two-dimensional media, and there is an acknowledgment of potential confusion in the initial sketches.

singleton
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Well, I'm learning plane sketching in R3.

One of the questions is 5y- z - 10 = 0

It is my understanding that the y intercept will be 2, and the z intercept will be -10.

With the absence of an x-term it should be parallel (?) to the x-axis.

I sketch the three axis, note the two points (0,2,0) and (0,0,-10) as the intercepts, but I have no idea how to actually draw the plane itself from this point on.

Unfortunately I have no scanner available to me to even show you what I have so far.

If you can even (verbally) suggest how I draw it, that'd be great.
 
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To clarify, I have the two points selected, but I just don't understand how I could draw a rectangular section that would be parallel to the x-axis.

It looks...skewed
 
x can be anything. if you draw the line 5y-z=10 in the yz-plane & then imagine lifting it straight upwards you'll get your plane.
 
An easy way I keep track of planes: if the equation is
[tex]a x + b y + c z = d[/tex]

then a normal vector is
[tex]\vec{n} = a \hat{x} + b \hat{y} + c \hat{z}[/tex]

If you think about it long enough it'll become intuitive. A plane z=constant, is parallel to the xy-plane, so the normal vector goes straight up in the z-direction.
 
fourier jr said:
x can be anything. if you draw the line 5y-z=10 in the yz-plane & then imagine lifting it straight upwards you'll get your plane.

aha!

I think I understand it now. I believe that I was going about it the wrong way. It just looked a little funny with the way I drew the x axis. Hard to comprehend three dimensions on a two dimensional paper :D

Later today I'll try and draw it in MSPaint :D
 

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