Find Equation of Plane from 2 Points | Equidistant

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In summary, to find the equation of a plane consisting of all points equidistant from points (2,5,5) and (-6,3,1), you can find the midpoint between the two points, (-2,4,3), and use the vector from that point to either of the two points as the normal vector. The equation of the plane can then be written as 4x + y + 2z = 2.
  • #1
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Homework Statement



find equation of a plane consisting of all points equidistant from points (2,5,5) and (-6,3,1)

Homework Equations



equation of a plane is
ax + by + cz + d = 0 where d = -(ax0+by0+cz0)

The Attempt at a Solution



can this be solved by finding the midway point of the line made by those two points, then using the vector from the midway to one point as a normal to the plane?

i just don't know how to find coordinates for that midpoint. i only know how to find the length of the line. its not just halfway between 2 and -6 for x and 5 and 3 for y and 5 and 1 for z is it?
 
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  • #2
The midpoint between two points (a,b,c) and (d,e,f) is going to be ((a+d)/2, (b+e)/2, (c+f)/2). And then, yes, use the vector from that point to either of your two points as a normal vector.
 
  • #3
so the midpoint of those two points, the one on the plane, is (-2,4,3) and so the normal vector is from that point to (2,5,5)
does that make the vector coordinates <4,1,2> ?

and then using equation for plane that passes through point (2,5,5) with normal vector <4,1,2>

a(x-x0) + b(y-y0) + c(z-z0)

becomes

4(x-(-2)) + 1(y-4) + 2(z-3) = 0
4x + 8 + y - 4 + 2z - 6 = 0
4x + y + 2z = 2

and that's the equation of the plane?
 
  • #4
Seems to check out for me.
 
  • #5
thank you
 

FAQ: Find Equation of Plane from 2 Points | Equidistant

1. How do I find the equation of a plane from two given points?

To find the equation of a plane from two points, you can use the point-normal form of the plane equation. This equation is (x - x0, y - y0, z - z0) · n = 0, where (x0, y0, z0) is one of the given points and n is the normal vector of the plane.

2. What is the significance of the term "equidistant" in finding the equation of a plane?

The term "equidistant" means that the distance from any point on the plane to both given points is equal. This condition ensures that the plane passes through the midpoint of the line segment connecting the two points and is perpendicular to the line segment.

3. Can I find the equation of a plane if only one point is given?

No, you need at least two points to uniquely determine a plane. If only one point is given, there are infinitely many planes that can pass through that point.

4. How do I know if the equation of a plane is correct?

To check if the equation of a plane is correct, you can plug in the coordinates of the given points into the equation and see if it satisfies the equation. Additionally, you can also check if the normal vector of the plane is perpendicular to the line segment connecting the two points.

5. Is there a different method for finding the equation of a plane from two points if the points are in 3D space?

No, the same method can be used to find the equation of a plane from two points in both 2D and 3D space. However, the resulting equation may have different coefficients depending on the coordinates of the points and the orientation of the plane.

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