When did you first encounter "proof based" mathematics?

Lavabug

I remember proofs as far back as geometry and precalculus/trig before university, I don't know remember when exactly, but I'm pretty sure I had precalc/trig in 9th or 10th grade, since I had calculus in 11th (not a US student).

My university encounters with calculus (also Spivak/Apostol and later Marsden) and linear algebra in my first year of university also did not skimp on the proofs. I don't remember proofs in high school calculus.

WannabeNewton

This is quite normal if one takes an honors calculus sequence. The usual suspects are either Spivak or Apostol if the course is any good.

thephystudent

I also learned my first proofs in high school, first geometrical like proving that two triangles were congruent, but i think my first "serious" proof was that sqrt(2) is irrational.

I agree that many theoretical math proofs are rather useless for physics and you simply don't have the time to learn the same background for all the math you use as a mathematics student does. But i believe one of the basic things about becoming a physicist and a scientist in general is being critical and question everything. And it's definately useful to know were basic math as l'hôpital's rule or the chain rule come from, knowing why this stuff works so why you can appy it.

alissca123

Well, I don't find proofs useless... I believe that the things you learn in physics make a lot more sense if you know proof based math.

For example, take Laplace's equation, I'm sure that the first method that comes to your mind is separation of variables, but why can you make the assumption that the solution is a product with the variables separated? How do you know it will work? A lot of physicists just scratch their heads and say "well who cares! it works!", but if you knew the math, you'd know that it has to do with the symmetries of the Laplacian, the method actually makes sense!

Maybe proofs are useless when calculating stuff, but they make things a lot clearer (at least for me)...

Devils

I've read that there is a way of doing the standard school geometry problems WITHOUT the standard proof method. To make it more intuitive for kids and stop them hating maths.

Anybody know anything about this?

WannabeNewton

I hope to god this isn't an actual thing. The last thing we need is a dumbing down of the already sub - par average high school math curriculum. i agree the way they teach proofs in those geometry classes is atrocious however.

micromass

So, what do you propose? Just giving out the statements and let the kids memorize that? Yeah, that way they're gonna stop hating math.

While I agree that high school geometry classes have a lot of problems and could be improved a lot, I don't think proofs is something we want to eliminate. What should be eliminated are stupid things like two-column proofs and memorizing definitions of obvious and useless terms (seriously: high school geometry books seem to get high from defining useless terms that nobody really cares about).


Furthermore, geometry is a field with a very rich history. But this rarely gets told in the classroom. One can use geometry to make a link to so many exciting subjects: for example, when I was in geometry, we learned as an axiom that through every point there exists a unique line parallel to a given line. I find it a shame that they didn't pick up a sphere and show that this wasn't true there. They also could have made connections to modern physics and they could have told us that our space is not euclidean. All of these things would make geometry class so much more exciting. But no: my entire geometry class was just a collection of dry facts nobody really cared about.

Devils

I cant find the web page that I was looking for but here is a book with similar ideas:

http://www.amazon.com/Proofs-without.../dp/0883857006
"Proofs without Words: Exercises in Visual Thinking (Classroom Resource"Materials) "

I have education & math degrees & some kids are visual learners. I've marked many high school math papers where kids "just dont get it", and the job of educators is top help the worst as well as best students. If alternative strategies are needed then so be it.

moouers

Like others, my first experience with proof-based mathematics was a geometry course during my freshman year of high school. I wasn't very good at it then, because I didn't put a lot of effort into learning the material needed to formulate a proof.

moouers

That is, word for word, exactly what my high school geometry teacher demonstrated for us. I was quite blessed to have him as my teacher for four years.

pk1234

First year at university now, the whole 1st semester is full of proofs in both real analysis and linear algebra. Quite different from high school - the only proofs I remember from there are things like "square root of 2 is an irrational number."

Surprisingly, I find the real analysis proofs easier compared to the linear algebra ones, unlike most of the other students - while the the proofs in linear algebra are simple and obvious, the technical part of writing them down with all the various indexes makes it very confusing... It's weird to me that writing down some linear algebra proof can be so long and tedious, when the "idea" behind the proof is so straight forward.

Might be because of the more "systematic" nature of the subject? I don't know.

Tsunoyukami

I first encountered proofs in Grade 11 (I am Canadian and unsure of what this translates to in terms of a US equivalence). The only proofs we did were basic trigonometric proofs.

However, when I entered my first of university I was overwhelmed with the number of proofs in my first-year calculus class. I felt as if I "understood" the proofs (in that I could read one and understand what was happening and was able to follow the logic) but I was unable to prove things myself. The class assumed you were already familiar with proofs and I did poorly in it.

Since then the math classes I have taken have been at an applied level as opposed to a theoretical level for the most part.


I feel as if most high schools do a poor job of preparing students for rigourous proof based mathematics.

Robert1986

This thread is interesting to me. I am a US student and I've lived here my whole life. I took Calc. I, II, and III as well as linear algebra before encountering what I would consider a real "proof-based" class. Sure, there were proofs mentioned in the calc classes and we did some "baby proofs" in linear algebra (prove this thing isn't or is a subspace, etc). My first real proof-based class was probably the second semester of my second year in college.

I find it interesting that people do proofs in high school (though, I wouldn't call most geometry classes 'proof-based') or as freshmen in college. Those of you who have done that, are you in school in the US? or somewhere else?

homeomorphic

An example that is somewhat along these lines is Curves and Surfaces: A Practical Geometry Handbook. It does have proofs, but they are somewhat non-rigorous at times. The point is to get a lot of intuition about why things are true, rather than dotting all the i's and crossing all the t's. In particular, the book discusses how. I would tend to suspect that it would work best for "gifted" children, but a really good teach might be able to convey it to a wider audience.

I think it makes sense to just introduce kids to the intuition of why things are true first, before doing formal proofs. That will help some of them stop hating math. Non-rigorous proofs are the core of math--those are the things you can actually take away and remember and gain insight from. The formal ones are just to check it all and make sure nothing goes wrong. The formal side is important, too, but it can't take the place of deep understanding.


The proofs aren't the problem. The problem is emphasizing formal proofs over seeing satisfying reasons why things should be true intuitively. But, I think if you started with non-rigorous proofs, that would come across better.


Those things are interesting, but personally, I think ruler and compass constructions are really fun. If I were to teach geometry, I might do it like Euclid does--doing geometric constructions and showing why they work, but a little bit less formally. These kinds of geometric constructions might arise in surveying or drafting, so you can see the usefulness and the beauty of it together.

homeomorphic

I don't think that visual learners should be considered the "worst" students. They are really the best students. In fact, the main reason I find so much math to be "dumbed down" is because it is targeted for people who have difficulty with visualization. If visual learners seem like they have trouble, it's the math that is wrong and the students who are right. The fact of the matter is that it is often, but not always the case that ONLY the visual thinkers are capable of a really deep understanding because there are many cases where if you can't visualize it, you don't really understand it. Of course, there are some visual learners who aren't that good at math, and some people who excel at non-visual aspects at math who aren't very visual thinkers, so I'm not saying it's an absolute rule that visual thinkers will be "better" students, just that visual thinking is sometimes necessary for a deep understanding of certain topics. Also, it is possible to try to visualize too much. People who aren't that good at visual thinking might think that it's a handicap, and sometimes it can be in a kind of screwed-up way, but it's only because of the WAY the material is presented, rather than something inherent in the material. The visual thinkers will outperform everyone else, given proper explanations of things.

pk1234

I'm in Europe. It's not like at my university everywhere, but generally across Europe, I think real analysis is compulsory for math students in first semester, if the school has any reputation. If you're a financial math student/informatics/physics however, the proofs aren't emphasized as much, with the exception of financial math, where calculus is taught instead of analysis, and the amount of proofs there really is minimal - there's some "important" proofs taught in the first semester (from around arithmetic of limits to l'hopital's rule, but a lot of things are skipped), but after that it's really just counting problems.

I think it's a bit of a tradition really. The attitude of all the professors (not just the analysis professors) is basically "analysis and linear algebra are basic subjects of higher math, upon which advanced math is based, and as such they should be taught as early as possible."

Best Pokemon

Physics schmysics! That would only make it worse, especially for girls.