# Thread: Mathematic Terminology

1. ## Mathematic Terminology

Hey so I have 2 questions;

8. What is the equation of the line that is perpendicular to the line $y=3x+2$ and contains the point $(1,-2)$?

9. Which common, but improper use of jargon is used in question 8?
I can't see anything wrong or mis-construed in the wording of number 8, am I missing something?

Thanks!

2. Originally Posted by Craigston
Hey so I have 2 questions;

I can't see anything wrong or mis-construed in the wording of number 8, am I missing something?

Thanks!
There is nothing wrong with that question.

Do you know what it means for a line to be perpendicular to another line?

3. 2 lines are perpendicular when their slopes are negative reciprocals right?

For number 8, I found the line perpendicular to $y=3x+2$ to be $y=-\frac{1}{3}x-\frac{5}{3}$.

But I still just wonder about number 9, should I just put that there is no incorrect jargon? The author seems pretty adamant that there is something wrong with it. I look too much into these I think haha, thanks for the help!

4. Ha - for some reason question 9 I did not see. As for jargon - that would refer to a definition that is being used improperly. I am missing something as well as the only words in question would be: equation, line, perpendicular and contains.

If I were a betting man, I would suggest he has a problem with the word "contain". Generally you will see "passes through", although if you Google you will see "contains" used as well. That is what I would put my money on (and if so, what a silly thing to be particular about at this stage).

5. Originally Posted by ANDS!
Ha - for some reason question 9 I did not see. As for jargon - that would refer to a definition that is being used improperly. I am missing something as well as the only words in question would be: equation, line, perpendicular and contains.

If I were a betting man, I would suggest he has a problem with the word "contain". Generally you will see "passes through", although if you Google you will see "contains" used as well. That is what I would put my money on (and if so, what a silly thing to be particular about at this stage).
Yeah that's what I was thinking, as I usually see "lies on" or "holds valid for the point".

I don't really see contains used much, but he used it for questions 5,6 and 7 too... I'm not a fan of these language arts questions hidden in my math book.

6. Originally Posted by ANDS!
Ha - for some reason question 9 I did not see. As for jargon - that would refer to a definition that is being used improperly. I am missing something as well as the only words in question would be: equation, line, perpendicular and contains.

If I were a betting man, I would suggest he has a problem with the word "contain". Generally you will see "passes through", although if you Google you will see "contains" used as well. That is what I would put my money on (and if so, what a silly thing to be particular about at this stage).
I would tend to agree with ANDS!.If there is a problem with anything I'd say it's most likely "contains". You might say "the point lies on..." or "the line passes through..." instead. It's the only thing that I see that looks a bit questionable.

7. Originally Posted by Craigston
Yeah that's what I was thinking, as I usually see "lies on" or "holds valid for the point".

I don't really see contains used much, but he used it for questions 5,6 and 7 too... I'm not a fan of these language arts questions hidden in my math book.
Ha. I was actually thinking, if I become a math instructor, that I would have questions like that on my tests! Is this an instructors test, or one from a book. Hopefully your instructor is teaching with this in mind, because if he isn't explaining the concepts that the book wants you to know - then he is screwing you guys.

It is important though to know what a concept means - I mean in the beginning, theres not a whole lot you have to worry about, but you're gonna find as you move further along in math that definitions are super crucial to understanding math.

But yes, I'm going to go with contains.

8. Well, I've taken pre-calculus and intro calculus, and I've got a bit of a taste of definitions and proofs such as the delta-epsilon limit definitions and the like, but this question just seems wierd. I got accepted into Engineering for the fall, and they sent this 15 page booklet of problems to work on to have completed before the school year. I guess to make sure we know what we need to know going i suppose.

But yeah, I just starting working on it and felt dumb that this question 9 boggled me haha.

9. Originally Posted by Craigston
8. What is the equation of the line that is perpendicular to the line and contains the point ?

9. Which common, but improper use of jargon is used in question 8?
Another possible issue, still concerning "contains", is that it could be slightly ambiguous as to which line the point is concerned with, i.e. misplaced modifiers. Granted that's more of a grammatical issue.

10. i believe it is "contains" also because look at q9. it tells you that it is common. and as ANDS implied, it is common.

also a line strictly doesnt contain anything. unlike $x^2+y^2 \leq 9$ contains the point (0,0).

also this is the worst question i have ever seen.

11. Originally Posted by Krahl
also a line strictly doesnt contain anything.
That is strictly nonsense.
It is quite common to say that a line is a point set containing at least two points.
That is standard in any course on axiomatic geometry.
As far as this current discussion goes, just consider that the original question was apparently written by an engineer not a mathematician.

12. Originally Posted by Craigston
Hey so I have 2 questions;

I can't see anything wrong or mis-construed in the wording of number 8, am I missing something?

Thanks!
"y= 3x+ 2" is NOT a line. It is an equation that describes a line. Sounds like the person who wrote this question is as picky as I am!

13. Originally Posted by HallsofIvy
"y= 3x+ 2" is NOT a line. It is an equation that describes a line. Sounds like the person who wrote this question is as picky as I am!
Good catch. I just skimmed right over that one.

14. Originally Posted by Plato
That is strictly nonsense.
It is quite common to say that a line is a point set containing at least two points.
That is standard in any course on axiomatic geometry.
As far as this current discussion goes, just consider that the original question was apparently written by an engineer not a mathematician.
I'm just curious as I'm going into my post-secondary education, I know that degrees in Engineering and Mathematics are vastly different, but I'm wondering how that would affect the perspective on this high school level question?

I hope this doesn't sound offensive, just curiosity about the 2 areas.

"y= 3x+ 2" is NOT a line. It is an equation that describes a line. Sounds like the person who wrote this question is as picky as I am!
That's gotta be it, thanks HallsofIvy!

15. The funny part is that a person who had never studied graphs might have wondered what in the world "the line y= 3x+ 2" meant!

Page 1 of 2 12 Last