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Planes watch

1. Hey.

Is it incorrect to say "three points define a plane" and correct to say "three points which do not lie on the same line define a plane"?

I think this is the case yet I keep on reading in my textbook that three points define a plane. I know this may appear pedantic but this is an important distinction to make.

Thank-you.
2. You're right. Textbooks often say things like "three points" when they mean "three non-collinear points", but good on you for spotting it anyway.
3. (Original post by Magu1re)
Hey.

Is it incorrect to say "three points define a plane" and correct to say "three points which do not lie on the same line define a plane"?

I think this is the case yet I keep on reading in my textbook that three points define a plane. I know this may appear pedantic but this is an important distinction to make.

Thank-you.
Your definition is a little less vague than theirs; they have missed an important point by not saying that. It is true that they must not lie on the same line otherwise you would have an infinite number of planes with these three points lying on them rather than a uniquely defined one.
4. (Original post by Farhan.Hanif93)
Your definition is a little less vague than theirs; they have missed an important point by not saying that. It is true that they must not lie on the same line otherwise you would have an infinite number of planes with these three points lying on them rather than a uniquely defined one.
A little less vague! Haha

I was not really making a definition as such; just checking a statement was true. :P And I'd have asked you but you weren't on FB!
5. (Original post by Farhan.Hanif93)
Your definition is a little less vague than theirs; they have missed an important point by not saying that. It is true that they must not lie on the same line otherwise you would have an infinite number of planes with these three points lying on them rather than a uniquely defined one.
Farhan you often sound too arrogant when giving advice. You should try to sound less arrogant, it will get you further. I don't wish to offend you by saying this.
6. (Original post by methusaleh)
Farhan you often sound too arrogant when giving advice. You should try to sound less arrogant, it will get you further. I don't wish to offend you by saying this.
Could I ask you to PM me what has given you the impression that I'm arrogant?

I'm not offended, just surprised that's all. I've made almost 5000 posts on TSR to date and no one has ever mentioned this before, nor has this been mentioned in day-to-day conversation.
7. (Original post by Farhan.Hanif93)
Could I ask you to PM me what has given you the impression that I'm arrogant?

I'm not offended, just surprised that's all. I've made almost 5000 posts on TSR to date and no one has ever mentioned this before, nor has this been mentioned in day-to-day conversation.
Perhaps I'm being over-sensitive, but its just the impression I get of your character. I think you post useful stuff, but I think what you post/say would be better appreciated if you posted less cockily.

I suppose its also hard to tell whether some1 is arrogant from behind a computer screen.

Again, no offence is intended.
8. (Original post by methusaleh)
Perhaps I'm being over-sensitive, but its just the impression I get of your character. I think you post useful stuff, but I think what you post/say would be better appreciated if you posted less cockily.

Again, no offence is intended.
I guess different people interpret others in different ways. You shouldn't really be judging my character from just reading my posts, though. My apologies if any of my posts have caused you to become irritated with my style of posting help on here.

I don't think I've been "cocky" in this thread, at all. Please feel free to tell me what part of my post was cocky.

We are now bumping a thread that has already been solved to the top of the maths forum, can we move over to PM?

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