Finding the scalar equation of a plane

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SUMMARY

The discussion focuses on finding the scalar equation of a plane defined by three points: P = (3, -1, 2), Q = (8, 2, 4), and R = (-1, -2, -3). To determine the normal vector to the plane, participants confirm that the cross product of vectors PQ and QR, or PR and QR, can be used interchangeably. Additionally, it is established that any of the three points can be used as the reference point (x0, y0, z0) in the plane equation without affecting the outcome.

PREREQUISITES
  • Understanding of vector operations, specifically cross products
  • Familiarity with the equation of a plane in three-dimensional space
  • Knowledge of point coordinates in 3D geometry
  • Basic algebra for substituting values into equations
NEXT STEPS
  • Study the properties of cross products in vector mathematics
  • Learn how to derive the equation of a plane from three non-collinear points
  • Explore different forms of the plane equation, such as parametric and symmetric forms
  • Investigate applications of planes in 3D graphics and computational geometry
USEFUL FOR

Students in geometry or linear algebra courses, educators teaching vector mathematics, and anyone interested in understanding the geometric representation of planes in three-dimensional space.

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Homework Statement


Find the equation of the plane that goes through points P, Q and R. P = (3, -1, 2), Q = (8, 2, 4) and R = (-1, -2, -3)

Homework Equations


Eq of plane
0 = a(x - x0) + b(y - y0) + c(z - z0)

The Attempt at a Solution


In order to find vector normal to the plane, my teacher took the cross product of PQ X PR. Would I still get the correct normal vector if I take the cross product of PQ X QR? Finally, when I plug in the numbers to the equation in "

Homework Equations

", does it matter which point I choose (P, Q or R) for x0, y0, or z0? Thank you.
 
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Calpalned said:

Homework Statement


Find the equation of the plane that goes through points P, Q and R. P = (3, -1, 2), Q = (8, 2, 4) and R = (-1, -2, -3)

Homework Equations


Eq of plane
0 = a(x - x0) + b(y - y0) + c(z - z0)

The Attempt at a Solution


In order to find vector normal to the plane, my teacher took the cross product of PQ X PR. Would I still get the correct normal vector if I take the cross product of PQ X QR? Finally, when I plug in the numbers to the equation in "

Homework Equations

", does it matter which point I choose (P, Q or R) for x0, y0, or z0? Thank you.
Yes, you can use PQ×QR or, for that matter, PR×QR . Each gives a vector which is normal to the plane.

No, it doesn't matter which point you use. Try more than one and compare results.
 
SammyS said:
Yes, you can use PQ×QR or, for that matter, PR×QR . Each gives a vector which is normal to the plane.

No, it doesn't matter which point you use. Try more than one and compare results.

Thank you
 

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