Taken a break from math? Would it be wise to jump back into Calc 2 or slow down with Calc 1

Hello I’ve taken a 3 year break from traditional university and I’m just getting back into next semester, the highest math I have taken is calculus 1 (3 years ago) right now I’m taking calc 1 on khan academy to refresh myself. Would it be wise to jump right into Calc 2? Additionally what are the general prerequisite knowledge for linear algebra. Thank you!

submitted by /u/AviationAdam
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Any interest in alternative forms of math?

A side project of mine has been to create an alternative system of math that is as useful and true for all the things we use math for yet to do it with different concepts and ideas to act as counterpoints to illuminate the aspects of math that are truly universal vs the aspects that could develop very differently. For example, if we met aliens, what aspects of their could be very different from our own.

One such aspect is that negative vs positive is handled differently and is not a trait of a number, but rather is a trait of context and handled separately from computing magnitude.

Is anyone here interested in hearing about it or discussing it?

submitted by /u/darklighthitomi
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YouTube Channels to watch

I’m looking for builds, rebuilds, restores, tunes, creative monsters, passion for cars in general, and general wrench turning. Alsø, alsø, wik SEMA coming up, who all has builds to watch for? What YouTube channels do you recommend?

Currently I watch these on the regular (not linking cuz I’m not sure what the rules are there… if it’s allowed, LMK and I’ll link it up):

  • B is for Build – Unique re/builds from salvage. Plays like he barely knows what he’s doing, but it’s clear it’s all about the journey. I live vicariously through Chris. (SEMA build: Texas Speed LS swap/fire damage rebuild/car porn body kit Lamborghini Huracán)
  • Cleetus McFarland – Over the top ‘murica but all around fun on drag builds
  • Rob Dahm – Pure. Unadulterated. Rotary porn. Straight up… err, I guess more like all around being rotary focused. (SEMA build: 4-rotor RX7 that’s been in the works for years)
  • Tavarish – Exotic builds + tangible builds (SEMA build: Fast & Furious Lamborghini Murciélago fantasy restore)
  • Ronald Finger – This guy is just fun to watch rebuild his Fiero in an every-day/every-person fashion
  • Scumbag Labs – As the co-hosts were to Mythbusters’, these guys are to Hoonigan. Ridiculous experiments. Lots of fun.

submitted by /u/beau6183
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Vector Transformations in Linear Algebra

I hope I’m posting in the right place. I have no clue where I’m going wrong with this question.

If T is defined by ​T(x​)=Ax​, find a vector x whose image under T is b​, and determine whether x is unique.

Concrete example:

A =

1 -4 -4
-2 -2 -4

b =


I would prefer to know the concept, but if using this example (sorry for awful formatting) helps, that works too! Thank you!

submitted by /u/TorponProtedos
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[Q] My model has an AUROC of 0.55 but a precision of 0.9 and a recall of 1.0. How is this possible?

I am using sklearn and some scripts to generate a 5 fold cross validation to obtain the metrics. I don’t know how I am getting these numbers though. Isn’t ROC AUC basically accuracy. And isn’t accuracy derived from precision and recall?

submitted by /u/logicallyzany
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Picked up an Elantra GT N-line


I was looking for a new car for my commute and landed on the Elantra GT N-line. I think it was a great little package that doesn’t get a lot of press. It wouldn’t have been on my radar if not for the recent buzz around the Veloster N. So, I thought I would write up my thoughts sort of like a “What car should I buy” post-mortem.

What did I buy?

  • 2019 Hyundai Elantra GT N-line
    • White ext / black int
    • 6 spd manual
    • No other options (manual is only trim, you need to get the DCT to get the tech pkg)
  • Price: $21,485 before tax, title, blah, blah, etc

My criteria:

  • Manual transmission
  • Compact hatchback / 5 door config
  • Good power (I live at elevation and often drive up the canyons so I wanted more than most base trims)
  • Fun to drive
  • Decent fuel economy
  • Apple Carplay
  • Around $25k

For reference, I was thinking about a first gen Acura TSX as sort of reference vehicle. Good power, an absolute blast to drive, but can still be a civilized commuter car.

Cross-shopping list:

  • Honda Civic Si
  • Honda Civic Sport
  • Subaru Impreza Sport

Each car had its strengths and weakness. The Hondas had better shifters and the Si was definitely a better driver but I couldn’t get past the exterior styling and the interior was really a step behind. The Subaru was a great value, AWD is a nice perk, and was more fun than I thought it would be with the manual but it is really under powered.

Why no Mazda3 or VW GTI/Golf?

Mazda forces you into a higher price tier to get the manual and secondly I was concerned about getting a non-turbo option at elevation. On top of that, none of the dealers local to me had a manual option available for a test drive. I am curious to drive one eventually but I don’t think they could have competed on price.

On the VW front, my wife’s daily is an Alltrack (DCT) that we both really like. Mostly I wanted something different rather than another VW. I also really hate our local VW dealership.

On that note, Subaru and Hyundai both offered a really pleasant dealership experience. The Honda place I visited was an awful experience. They were really hesitant to let me test drive unless I was ready to buy one off the lot that day! Thankfully we were able to get past that. I get that they are a volume dealer but really left a bad taste in my mouth. The Subaru place here moves a ton of volume and was packed when I showed up but they still took time to treat me well. Luckily I have multiple dealership options around me but really disappointed in Honda here.

Is the Hyundai perfect? Of course not but it ended up being the right car for me. Thanks for reading. Happy to answer questions but I thought this might be useful for other shoppers.

submitted by /u/zachgs
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Did anyone else find their first year boring in their math undergrad?

I decided to major in math because of all those cool mind blowing videos about math on youtube and because I thought I was pretty good at it, but a month and a half in, it just feels so repetitive. Implicit differentiation is literally just a bunch of algebra and linear algebra is just doing a bunch of arithmetic with matrices (even though that can be fun sometimes). The only course I really enjoy is my “intro to real anaylsis” which is a course that’s designed to make your life much easier when you get to real anaylsis in second or third year, and I like that course because it actually explains a lot of concepts of math that I didn’t really understand before.

I looked through the courses I would take throughout my undergrad and found out that the cool math courses don’t start until around third year, so right now I feel like I’m just gonna be bored until then. Did anyone else feel this way in their first couple years?

submitted by /u/MacAltAccount
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Undergraduate taking Graduate classes?

Not sure if this kind of post goes here, but I’m not sure where else to post.

I’m a freshman going to a top 30 school, and I’m majoring in Math and Physics. This year, I will finish multivariable calculus, discrete math, linear algebra, and ODE. I am taking the standard physics route, but I seem to be a few years ahead mathematically of what they’re teaching. I am interested in taking graduate-level courses for either math or physics by my sophomore or junior year (mostly introductory-level graduate courses, e.g., Graduate Topology 1 vs Undergraduate Topology 1).

Are there any recommendations for accelerating myself? How can I make my case to the department that I am able to assume such an intense load so early? I’m prepared to work very hard.

submitted by /u/neuron_soup
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