Find equations of the plane (confirmation).

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Thanks a lot for your help!In summary, the problem is to find the vector, parametric and scalar equation of a plane passing through three given points. The solution involves forming a vector equation using the three points and solving for s and t, which can then be used to obtain the parametric equations. The scalar equation can be found by picking off the coordinates of a normal to the plane, which is obtained by taking the cross product of two vectors formed by the given points. The given points can then be substituted into the scalar equation to confirm the solution.
  • #1
NATURE.M
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Homework Statement



Find the vector, parametric and scalar equation of the plane passing through A(3, 5, 2), B(0, 5, −1) and C(1, 5, −3).

Homework Equations



Vector, scalar, and parametric equations of plane.

The Attempt at a Solution



For my solution:

vector equation:
[x,y,z]=[3,5,2]+s[-3,0,-3]+t[-2,0,-5], s,t εℝ (from this the parametric equations are quite intuitive.

i really would like to confirm the scalar equation i have for the plane:

-9y+45=0
 
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  • #2
NATURE.M said:

Homework Statement



Find the vector, parametric and scalar equation of the plane passing through A(3, 5, 2), B(0, 5, −1) and C(1, 5, −3).

Homework Equations



Vector, scalar, and parametric equations of plane.

The Attempt at a Solution



For my solution:

vector equation:
[x,y,z]=[3,5,2]+s[-3,0,-3]+t[-2,0,-5], s,t εℝ (from this the parametric equations are quite intuitive.

i really would like to confirm the scalar equation i have for the plane:

-9y+45=0
This is the same as y = 5, and your three given points satisfy that equation. If you want to convince yourself absolutely, form vectors AB and AC, and dot them with the normal to your plane, which happens to be <0, 5, 0> (or any multiple of this vector).

Edit: Make that <0, 1, 0> for a normal. Fortuanately for me, <0, 5, 0> is a scalar multiple of <0, 1, 0>.
 
Last edited:
  • #3
Mark44 said:
This is the same as y = 5, and your three given points satisfy that equation. If you want to convince yourself absolutely, form vectors AB and AC, and dot them with the normal to your plane, which happens to be <0, 5, 0> (or any multiple of this vector).

Thanks a lot. And for vectors AB and AC, the cross product I obtain from them is [0,-9,0], which is a scalar multiple of [0,5,0], so that makes sense.
 
  • #4
From the standard equation for a plane, Ax + By + Cz = D, you can pick off the coordinates of a normal to the plane: <A, B, C>.

For your plane, the standard equation is 0x + 1y + 0z = 5, so a normal would be <0, 1, 0>. I picked off the wrong number to get <0, 5, 0>, but as luck would have it, the two are multiples of each other.
 
  • #5
Okay, I just used the normal [0,-9,0] and the point A(3, 5, 2) to solve for the scalar equation, so 0x-9y+0z+d=0, substitute point A and we get y=5. But either way,the answer is the same.
 

1. What is the purpose of finding equations of a plane?

Finding equations of a plane is important in various fields of science and engineering, such as physics, aerodynamics, and structural analysis. It allows us to understand the relationship between different points and lines on a 3D plane, and can be used to solve problems involving surfaces, intersections, and distances.

2. How do you determine the equations of a plane?

The equations of a plane can be determined using different methods, such as using the coordinates of three non-collinear points on the plane, or by using the normal vector and a point on the plane. The equations can also be derived from the general equation of a plane, which is ax + by + cz + d = 0, where a, b, and c represent the coefficients of the plane's normal vector, and d represents the distance of the plane from the origin.

3. Can you find equations of a plane in any coordinate system?

Yes, equations of a plane can be found in any coordinate system, as long as the points and vectors used are consistent with the chosen coordinate system. For example, in a Cartesian coordinate system, the equations would involve x, y, and z coordinates, while in a polar coordinate system, the equations would involve r and θ coordinates.

4. Are there any limitations when finding equations of a plane?

There are some limitations when finding equations of a plane, such as the requirement of non-collinear points for certain methods, and the fact that the equations may not represent all points on the plane, but rather a specific region. Additionally, if the points used are not precise or there are errors in calculations, the resulting equations may not accurately represent the plane.

5. How can equations of a plane be used in real-world applications?

The equations of a plane have various real-world applications, such as in navigation systems, flight simulations, and architectural and engineering designs. They can also be used to analyze the stability and stress distribution of structures, and to determine the path of an object in 3D space. Additionally, the equations can be used in computer graphics to render 3D objects and environments.

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