intersections

Suppose P and Q are two distinct planes in R³. What sort of set could their intersection be?
Answer in words and give a sketch to show the possibilities.

Quote:

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Originally Posted by federer

Suppose P and Q are two distinct planes in R³. What sort of set could their intersection be?
Answer in words and give a sketch to show the possibilities.

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If they are parallel their intersection is the null set.

If they are not parallel their intersection is a straight line.

RonL

Quote:

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Originally Posted by federer

Suppose P and Q are two distinct planes in R³. What sort of set could their intersection be?
Answer in words and give a sketch to show the possibilities.

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Another point of view:
Two planes in R^3, correspond to 2 linear equations in three variables.
Now what can you tell about the solution to this system.

Can it have a unique solution?Can it have infinitely many solutions? Can it have no solutions?