Intersection of Two Planes
Given two planes:
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Form a system with the equations of the planes and calculate the ranks.

r = rank of the coefficient matrix.
r'= rank of the augmented matrix.
The relationship between the two planes can be described as follows:
| Position | r | r' | |
|---|---|---|---|
| Intersecting | 2 | 2 | |
| Parallel | 1 | 2 | |
| Coincident | 1 | 1 |
Examples
State the relationship between the planes.
1. ![]()
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For intersecting planes, the intersection is a line.
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2. ![]()
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Parallel planes.
3. ![]()
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Coincident planes.
