Comment by Raidion | Hacker News Reader

Comment by Raidion | Hacker News Reader

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I would assume (like everything else) most people fall on a Bell curve, where there is higher level math that's inaccessible to most people, but the math for daily use is (almost by definition) pretty useful.

I definietly think there are better ways to approach math, some like the theoretical perspective, some prefer the engineering approach "I need to solve this problem, and these are some tools to help us do so.

I'm not "good" at math (and I could dig out old college transcripts to prove it), but I do have a math minor because I really enjoyed the experimental engineering/physics/comp sci stuff, but found math classes on their own really boring. I feel a lot of people would benefit a more holistic approach to math, starting with algebra/geometry. It's just a mess of graphs and equations, and I struggled to find a reason to care, though I was fortunate to have a brain (and the cultural conditioning) that made those abstract "puzzles" interesting.

I got a B in Linear Algebra, and I still can't describe why you'd need that in the real world, while calculus/diff eq/discrete math were clearly tied to physics/thermodynamcis/computer science problems I knew.

To bastardize a famous quote: If you wish to build mathematicians, do not divide the men into teams and send them to the forest to graph equations. Instead, teach them to long for the vast and endless understanding of a problem that they find interesting.

> I got a B in Linear Algebra, and I still can't describe why you'd need that in the real world, [...]

Here is a short list of applications of linear algebra:

   - Balancing chemical equations
   - Input–output models in economics
   - Electric circuits
   - Graphs
   - Least squares approximate solutions
   - Computer graphics
   - Cryptography
   - Error-correcting codes
   - Fourier analysis

You can read about these in Chapter 7 of my book in LA. Here is an extended preview of it here: https://minireference.com/static/excerpts/noBSLA_v2_preview....

I think that what OP meant by "real world" is something closer to "daily life" use.

Something you'd encounter as Mr. random.

Well, in that case you need: addition, subtraction, multiplication and division. You could stop Math in 3rd grade for everyday life applications.

One needs to be able to do risk-benefit analysis of any credit lines.

> I got a B in Linear Algebra, and I still can't describe why you'd need that in the real world

seems odd in a world full of 3D graphics and machine learning, which are built on heaping piles of linear algebra.

I think this is one of the big advantages of a broad undergraduate education in math; the math that I use frequently looks very different from the math used by people in <insert other field>. I have essentially never used any calc/analysis/topology/geometry/number theory/etc stuff in the real world, but graph theory, stats, linear algebra, etc have come up a LOT. Which stands at odds with a lot of my college friends who need a completely different set of tools in their current work.

> I got a B in Linear Algebra, and I still can't describe why you'd need that in the real world, while calculus/diff eq/discrete math were clearly tied to physics/thermodynamcis/computer science problems I knew.

I thought this was an interesting comment, because I personally believe linear algebra is one of the most applicable topics in math and relates a lot to the topics you contrasted it with. For example, in multivariable calculus, derivatives of functions with multiple variables end up being linear maps, and understanding properties of those maps and how they're transformed helps a lot with understanding the properties of derivatives and how to apply them. Differential equations are solved in practice by approximating them as linear systems and solving those equations, so again, understanding linear algebra helps a lot there (e.g., eigenvalues are intimately connected to the ways differential equations behave). I'm not so familiar with discrete math, but I do know there are connections between linear algebra and some areas of graph theory (not sure how critical they are to those areas, though).

That's not meant as a criticism of your comment, because I think the way linear algebra courses are taught doesn't do much to make those connections clear. Intro courses focus a lot on mechanical problem solving and do a poor job of motivating concepts (e.g., I remember eigenvalue problems showing up mostly out of nowhere). In courses beyond the introductory level the presentation and focus is more abstract and does little to demonstrate why you would care beyond intrinsic interest. I think if more motivation or context were provided, it would help encourage those more interested in applications than math for math's sake to go deeper into a topic that can be very useful in a lot of applied areas.

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