- Видео 295
- Просмотров 634 927
Robert Cruikshank
США
Добавлен 14 окт 2011
Symmetric Difference of Sets is Associative
A short proof, illustrated with Venn diagrams, and using a symmetry argument.
Просмотров: 2 061
Видео
How Beta is Conjugate to Binomial
Просмотров 810Год назад
A derivation of the relationship between prior beta distribution, binomial data, and an updated beta distribution.
The Beta Function: Solving the Defining Integral for integer a,b
Просмотров 323Год назад
The Beta Function (as opposed to the Beta Distribution) is defined both by an integral and as a combination of gamma functions. I show the two are the same for the case of integer inputs. Wikipedia has more general proofs but I thought this case has more straightforward calculus.
CDFs for Exponential Rayleigh Weibull and Pareto Distributions
Просмотров 634Год назад
(revised) I show a pattern in the formulas for a few different probability distributions. These formulas are often scattered in a textbook so I brought them together.
Low Pass, High Pass, or Bandpass Filter?
Просмотров 3,7 тыс.Год назад
Almost zero math. Mnemonic and explanation for several simple cases of filter networks. This is for grasping the concept.
Counting Radial and Angular Nodes in Atomic Orbitals
Просмотров 1,8 тыс.Год назад
A Two Minute Video with the rules and four worked examples.
From Complex Roots to Real Solutions
Просмотров 1252 года назад
Here's a detail that often gets covered quickly in differential equations class. Apologies for the blurriness, I seem to be cursed when it comes to camera technology.
Electric power: Definitions (A Two Minute Video)
Просмотров 1542 года назад
Definitions of power, current and voltage, with brief examples. Made for a viewer by request!
What is E[E[X|Y]] ?
Просмотров 3182 года назад
I work a tiny example with numbers and give a symbolic proof at the end. Hopefully this reduces confusion!
Adding Vectors: TLDW Version
Просмотров 772 года назад
Here's the 2.5 minute version of the 16.5 minute video I just posted: ruclips.net/video/bKfto0MKFrg/видео.html Season to taste! #physicstutor #physics #tutoringservices #vectors
Adding Vectors: Every. Single. Step.
Просмотров 1352 года назад
This video is long; it assumes very little knowledge, and is meant for students facing most of the ideas for the first time. I have created a TL;DW version that zips through the same thing at 5x speed. ruclips.net/video/5Y79FUVpgUU/видео.html I hope this helps to save students struggling with the beginning of #physics class! #physicstutor #vectors #tutoringservices
A Tricky F = ma Problem from Kleppner and Kolenkow 1st ed
Просмотров 8892 года назад
I solve problem 2.19 from K and K in the first 2:30, then problem 2.20 in the rest of the video. linktr.ee/knowledgeoncall robertthetutor.online
Holder Inequality Lemma: A 2 minute proof
Просмотров 7792 года назад
The Cauchy -Schwarz Inequality is widely used; it turns out to be a special case of the Holder Inequality. That in turn depends on this little lemma, which can be proven with a bit of calculus. The proof is mostly taken from Casella and Berger.
Power and Intensity (an example with sound energy)
Просмотров 1792 года назад
I work an example of a speaker emitting sound, and talk about the energy, power, intensity, and sound intensity level (dB). This is another video made with slides and a VoiceOver. These certainly upload faster! I'm still getting the hang of making a voice over, so I didn't fight to trim this one down to two minutes flat.
How Voting Works
Просмотров 662 года назад
Just spelling out things that everybody should already know. Elections are much, much easier than civil war.
Why does the Fourier Trick Work? Using trig not integration by parts
Просмотров 1,1 тыс.2 года назад
Why does the Fourier Trick Work? Using trig not integration by parts
Moment and Shear All Along a Cantilever
Просмотров 652 года назад
Moment and Shear All Along a Cantilever
From Physics 1 to Engineering Statics: Cantilever Example
Просмотров 1072 года назад
From Physics 1 to Engineering Statics: Cantilever Example
Nodes and Antinodes in an Open Pipe
Просмотров 1,7 тыс.2 года назад
Nodes and Antinodes in an Open Pipe
100 cm^2 is NOT 1m^2! Visual Examples in Metric
Просмотров 1 тыс.2 года назад
100 cm^2 is NOT 1m^2! Visual Examples in Metric
Hydrogen and Energy (clearing up confusion)
Просмотров 1262 года назад
Hydrogen and Energy (clearing up confusion)
How to Clean a Quadra-Fire 1200-I Pellet Insert (Stove that fits inside a fireplace)
Просмотров 2,3 тыс.2 года назад
How to Clean a Quadra-Fire 1200-I Pellet Insert (Stove that fits inside a fireplace)
Deciphering the Definition of Complete Statistic
Просмотров 1,4 тыс.2 года назад
Deciphering the Definition of Complete Statistic
The Definition of Sufficient Statistic Looks Weird (a 2 minute remake)
Просмотров 1,1 тыс.2 года назад
The Definition of Sufficient Statistic Looks Weird (a 2 minute remake)
I have 3 little holes in the bottom of my firepot. How do I clean those?
I just use the ash vacuum myself, but I don't know the official way. Maybe I'm not supposed to do that.
Sir thankyou for explaining the series and parallel combination in a very nice manner now i understand very well about this topic
Thank you❤❤❤❤❤❤
The graph is really helpful to understand the concept. Thank you!
This was so helpful. Thank you!
Thanks, that’s really helpful
Thanks for the explanation! I wonder if they avoided defining the sufficient statistics by the posterior due to certain regularization conditions, like avoiding the marginal distribution is non-zero at certain points?
It's been pointed out to me that with a frequentist interpretation my description makes no sense. I'm not 100% sure of that, but my expertise is limited. I wasted ten hours wrapping my head around it so I wanted to spare everyone else those ten hours if I could.
Thanku sir you save my life 2 days before my engineering exam 🫡❤️🩹. Now I can do this circuit problems. Once again thanku
well taught!!
Thank you very much! There were a lot of definitions so I wanted to put them all together for easier comparison.
Thanks a lot sir for the explanation 🩵💛
Thank you 🙏🙏🙏 I am very grateful for your explanation sir 😊😊😊
🔥🔥
This is the best geometric interpretation of understanding 3 dimensional r theta pi coordinates. So much thanks.
Thank you Sir
Thanks a lot sir ❤
Very clear explanation. Nicely done! I say this having just done a Google search in which AI got this completely wrong. That freaked me out. Glad you are here.
Hi Robert, good video! Just about all Radio Shack learning kit(s) where produced by Elenco. Radio Shack(s) brand name for the basic learning Elenco Playground kit(s) was "Science Fair". In the mean time, you can still purchase Radio Shack Science Fair learning kit(s) under the name "Elenco Playground". By the way, Radio Shacks more expensive learning labs where produced by "Maxitronix". Maxitronix is also a brand of Elenco. Please reply. Dave...
Thank You
Thank you so much, this was the exact explanation I was looking for!
If you don't already have those 12 lemmas down cold I would expect Calculus on Manifolds to be an incredibly tough read. I loved the book but couldn't imagine having done it without the background I built up in single variable analysis from studying the first 7 chapters of Baby Rudin.
It was incredibly tough. But my problem was not so much seeing the truth as seeing the proof. For me, any proof system MUST explain EXACTLY what you are and are not allowed to assume. Otherwise a proof is just a plausibility argument. Since C on M gave almost nothing to work with, I had to build the tools that I kept instinctively reaching for. Once I proved these, I referenced them constantly in other proofs. I WANTED to just assume them, but I can't ever tell whether that's safe to do. (Incidentally, that's why geometry was the only math class I ever had problems with, because in high school all my proofs took 2 hours and multiple pages while everyone else was doing it in 3-5 lines for full credit.)
@@robertcruikshank4501 I just took it as a reasonable assumption that anything you saw in a single variable real analysis course could be assumed. I see people say you could read this book profitably after calculus and a linear algebra course but wonder if they're assuming we're Gauss or something haha. Though in my solutions to the problems when convenient I would use the Lebesgue integral when I could and when it simplified things.
Is the long line represent positive?
On the battery symbol you mean? Yes.
Nice and simple. thanks!
Thank you for the information. This was helpful.
sir could you explain what would happen with the intensity?
A smaller hole lets less light through overall.
@@robertcruikshank4501 but if I would to increase the size of pinhole why isn't the diffraction intensity decreasing cause diffraction is more predominant when obstacle is small
Thanks man!
This helped a lot when my prof didn't, thank you for making this
i am from India still watching this ❤
sab india se hi h babu 😂😂
Nitrogen has MW of 14 and not 28 as you mentioned but calcs are still based on 14.
Hold on: I understand you wish to say that little the PDF of Y is the derivative of the CDF of Y (i.e., the statements in the top-right corner of the whiteboard. However, you wrote that F_X(sqrt[y]) i.e., the cumulative distribution function of random variable X as a function of observed value sqrt(y) is 1/(2sqrt(y). You subsequently substituted this expression for F_Y(y) (i.e., the cumulative distribution function of random variable Y as a function of observed value y). is this appropriate? It seems like some amount of explanation would be needed, though? I.e., it seems that you simply used F_X(sqrt(y)) interchangeably with F_Y(y)
EDIT: Ah, nevermind, I see/am reminded now that earlier, we have a statement equating F_Y(y) to be equal to F_X(sqrt(y)). My attention was darting back and forth a little bit too much between different resources on the computer screen and my own sheets of paper haha. This has been a good struggle; I hope this will help me remember things for my subsequent tests and evaluations :)
I wonder: Is it sufficient to simply without justification that P(X^2 < y) is precisely equivalent to P (X < sqrt(y))? I know it's obvious that X is SQRT(X^2) and that sqrt y is SQRT(y), but is it also fully defensible to say that P(m<n) is always equal to p(sqrt(m)<sqrt(n))?
That's why I specified a positive domain. In general, if X^2 < Y, then -SQRT(Y) < X < SQRT(Y)
Provided that Tis symmetric, show that tr ( nabla* T)=0 I am really got confused on this topic
I can see why! I went hunting for definitions. nabla*T seems to be either rank 1 or rank 3 tensor, and in either case I don't know how "trace" makes sense. Trace is a contraction of a rank 2 tensor. When in doubt, study the definitions! You may have gotten a def in lecture or something. Figure out what nabla*T IS in the first place, and what the def of trace for it is. Good luck!
❤ amazing short and sweet
The reason why they have to switch it up in general is that the expression P(theta | U, data) = P(theta| U) does not make sense unless you're a Bayesian. If you're doing frequentist statistics, the parameter is not random, just unknown. This means that the expression P(theta) simply does not make sense. This also goes to show how many people are intuitively Bayesian to begin with hahaha.
Yes, I have heard this argument. As far as I can understand (which is limited), it leaves math behind and dives into philosophy. Granted, the philosophy of probability theory is seriously messed up to begin with. It wasn't until I tackled advanced statistics that I realized that I owed QM an apology for calling it nonsensical--it merely inherited most of its problems from probability theory. But to get back on point: if I fully understood the issue you are describing, I would have made another video about it. Sadly I must leave that to better minds than my own.
Thank you sir Tomorrow I am going to write a paper in Tesla in power systems
perfect, helped me understand this simple concept more effectively
Wow incredibly efficient video, thank you for helping me grasp this topic
Thank you I finally understood this 🙏
wow , thank you very much, it helps a lot
Thank you sir very very much for the information and by the way I had a doubt That why is biot savants law only restricted to steady state current flow?
It turns out that electric and magnetic field changes are limited by the speed of light. So it gets really complicated really quickly if you have to take into account exactly when and where the particle was moving how fast, the time lag makes it a mess to calculate. Steady state problems skip all that.
As of August 2024, a new fare payment system has been implemented on subways, buses and trolleys. In addition to paying with your charlie card, you can also tap your credit card, or a phone with a digital wallet on the new screens by the fare gate/box. Just make sure to tap your phone/credit card on the screen and your charlie card on the circle. Enjoy the T.
Clearest most understandable video I have watched in my life
Great video!
Very well made!
Thank you. Very easy to understand. Brilliantly explained. Respect from Pakistan.
absolutely great video
at 0:31 you say "pressure times volume has the units of work", but the whiteboard says "pressure times the change in volume has the units of work"
Both are true. Volume and change in volume have the same units.
Thanks!!
This video was incredibly helpful! Thank you for posting this.
I can't explain how much it useful for my exams. I was always confused in batteries one. You cleared all my doubts. Thanks a lot from India🇮🇳🇮🇳
Thanks! Also for the current we can choose any direction all the time?
Yes! It's just like choosing a coordinate system, there's no wrong answer. If you get a negative number for your current that means it is actually flowing the other way, just like if you say up is positive and get a negative vertical velocity it means the object is going down. Just be consistent.