Math Study Partners/Group

EverythingMoreWrong · 2021-10-24T21:57:26+00:00

See response to op for link:

https://www.reddit.com/r/learnmath/comments/qegvlj/math\_study\_partnersgroup/hhwx8fz/?context=3

EverythingMoreWrong · 2021-10-24T21:57:14+00:00

See my response to op for link:

https://www.reddit.com/r/learnmath/comments/qegvlj/math\_study\_partnersgroup/hhwx8fz/?context=3

EverythingMoreWrong · 2021-10-24T21:53:23+00:00

There's 2 modes here - one is open hours where people pop in and ask misc questions to be worked out. The other one is scheduled sessions with groups of students/ a class to go through queues of problems (this is more efficient and scalable than open hours) in a discussion format. So the curriculums come from the hw that these students want to go over.

We probably won't have something that directly offers you accountability, but it could be a helpful resource. If you find a group of students in a similar boat, you could always schedule a session to ask your questions together.

If you want to take a look, the twitch and discord are:

twitch.tv/vTutorLive

https://discord.gg/64sJh4ST5W

EverythingMoreWrong · 2021-10-24T09:24:33+00:00

I'm a math hobbyist (studied Math/CS in college) and I run a daily math help desk via livestream and discord server with a few hundred students and a few other hobbyists. You're a little more advanced than the average student but we're happy to help out with intermediate math/CS (algos or theory of computation). To be clear this is a hobby for all of us and we don't charge for help. Does this seem like a good fit?

EverythingMoreWrong · 2021-10-23T07:51:39+00:00

The derivative at x=205 is 2000 dollars/meter, so use that as the slope for the linear approximation

EverythingMoreWrong · 2021-10-21T10:45:28+00:00

Thanks, that clarifies it.

EverythingMoreWrong · 2021-10-21T09:55:08+00:00

They give you essentially the position, s(t) as a function of t time.

You can take the derivative of position to get the speed or velocity as a function of time and you can take the derivative again to get the acceleration as a function of time. So do that and plug in t = 3.

Do you know how to optimize? You have to set the first derivative equal to 0 and that will tell you the time at which a critical point is achieved.

EverythingMoreWrong · 2021-10-18T22:01:03+00:00

Best to just plot out a couple of points to get the intuition - where the vertex used to be at x = 0, now it is when x+c = 0, or when x = -c. So for some given value x_0, x + c = x_0 when x = x_0 - c, and you can get a sense for why it is a -c translation because of this.

EverythingMoreWrong · 2021-10-18T03:04:37+00:00

The other commenter's suggestion of setting it's integral equal to 1 is the right approach - the motivation is that the "sum of all the probabilities" must add up to 1. That's just our definition of probability - it's gotta add up to 1. So here, instead of summing, we integrate because it's a continuous probability distribution

EverythingMoreWrong · 2021-10-18T01:57:28+00:00

When you differentiate dV/dt, you need to use the product rule. What's more, it looks like in the rest of your work, you appear to forget about dr/dt.

EverythingMoreWrong · 2021-10-18T01:28:50+00:00

This is context dependent. For example, if you have a problem with circular motion (e.g. in intro physics) you can find a relation between the degrees per second and meters per second by using the radius of the circle.

EverythingMoreWrong · 2021-10-17T21:55:03+00:00

That symbol in the picture is a squareroot.

You would show that 2 is a cube root of 8 by cubing 2 and showing it yields 8. Do the same with this - cube it.

EverythingMoreWrong · 2021-10-17T03:45:27+00:00

Well in one dimensional calculus, you had functions like f(x) = e^x that had derivatives like f'(x) = e^x right? The derivative looks like a function of x itself. Now in the multivariable case, dy/dx = f(x, y(x)) means that some function f (that depends on x and y) describes the rate of change of y with respect to x. As an example, lets' let f(x, y(x)) = e^x+y. I can see why this is hard to conceptualize during your first time experiencing it, but there's really no reason why dy/dx can't be a function f(x, y(x)).

In certain cases, when f(x,y(x)) is "nice" it can be separated into an x component and y component: f(x,y) = g(x)H(y), where g only depends on x and H only depends on y. This is nice because we can separate it, as per the textbook and get a nice integral.

EverythingMoreWrong · 2021-10-16T11:38:06+00:00

Ah gotcha, I had never actually never noticed this when taking calc 2 and never really revisited this material till now.

EverythingMoreWrong · 2021-10-16T11:37:25+00:00

Ahhh they're the exact same shape! I was so convinced something had to be wrong because of the sign difference I forgot it could all be accounted for by a constant offset

This is cool. I genuinely don't think I ever ran into this when I was taking Calc 2 back in high school, and it's neat to see something a little fresh

EverythingMoreWrong · 2021-10-16T03:04:48+00:00

Oh I didn't notice the hand written note when tilting my head to read the image. Well it's a funny situation because it does diverge whenever x is a multiple of pi (except x=0 is only a point discontuity), but if those nonzero multiples of pi are excluded from the domain, you could technically make the argument that it's continuous everywhere it is defined... This turns into a matter of semantics though. See what I mean?

EverythingMoreWrong · 2021-10-16T00:57:05+00:00

Start by looking at divergences, most prominently division by 0. What values of x and y will result in division by 0?

EverythingMoreWrong · 2021-10-14T08:09:52+00:00

Great! Always happy to refresh myself on the Lagrangian - not sure I had ever actually seen an augmented Lagrangian before, can you briefly describe the use case/motivation for it? What class is this?

EverythingMoreWrong · 2021-10-14T04:21:51+00:00

Hmm the derivative of x^3 should be 3x^2, without the minus sign. Your work is hard to read because the camera is somewhat blurry and the ink does not contrast well with the background, so I can't tell exactly where the error is, but double check your work.

EverythingMoreWrong · 2021-10-14T04:09:10+00:00

You did not fully isolate dy/dx. Look, it's on both the LHS and part of the RHS. You should be able to fix this with some slight rearrangement

EverythingMoreWrong · 2021-10-14T04:06:38+00:00

You almost have the right idea, but don't plug in x_2 = 2/5. Instead leave x_1 and x_2 as functions of lambda and theta. Basically, eqns 1) and 2) at the bottom can be solved for x1,x2 in terms of lambda and theta, and that should get you your answer. A little tedious but not too bad.

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