Differential Equations: Lecture 1.1-1.2 Definitions and Terminology and Initial Value Problems

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  • Опубліковано 22 гру 2024

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  • @jimkane7162
    @jimkane7162 4 роки тому +409

    The difference b/w you and other professors is that you can keep students awake and interested for a full one hour. Enjoyed your enthusiasm.

    • @TheMathSorcerer
      @TheMathSorcerer  4 роки тому +38

      Thx👍

    • @aliAlyacoub
      @aliAlyacoub 2 роки тому +21

      Not only that, but he keeps the lecture based! He doesn't talk about stuff the students do not have a clue about. It means he genuinely wants to teach, not just show off his brilliance as some teachers do.

    • @terjeoseberg990
      @terjeoseberg990 Рік тому +1

      But the camera can’t keep up.

    • @Primitive_Code
      @Primitive_Code Рік тому

      ​@@aliAlyacoubYep, as a math major myself I know exactly what you're talking about. I don't know what the teachers accomplish by doing that exactly.

  • @gabrielnicolosi8706
    @gabrielnicolosi8706 4 роки тому +21

    I'm amazed how in the comments we see students from "prestigious" universities claiming these lectures helped them more than their professors... People pay thousands and get in life long debt for a fake and forced education whereas professors like the one from this series of videos are barely recognized. Congratulations Math Sorcerer, your honesty in teaching is what makes you so genuine and successful at what you do!
    Gabriel

  • @VndNvwYvvSvv
    @VndNvwYvvSvv 3 роки тому +63

    I'm glad there are people like this putting their work online and speaking in more easily understood terms than the text.

  • @426F6F
    @426F6F Рік тому +11

    Wow, you're the best math professor I've ever seen! Your enthusiasm, depth of understanding and engagement with the class is fantastic!
    It must not feel intimidating at all for students to ask you questions because you're such a genuine dude! Please don't ever change!!

  • @urmom-ld5ku
    @urmom-ld5ku 4 роки тому +498

    my professor posts your videos, so he doesn't have to teach :^) congrats on your new job at my university!

    • @VndNvwYvvSvv
      @VndNvwYvvSvv 3 роки тому +61

      Oof, I'm sorry. What a garbage professor. This is a good series, but they should still do the work you're paying so much for. I'm glad there are people like this putting their work online and speaking in more easily understood terms than the text.

    • @happyface4234
      @happyface4234 3 роки тому +8

      @@VndNvwYvvSvv He prob use in-class time to do research anyway.

    • @mr.radium4962
      @mr.radium4962 2 роки тому +11

      It's better than not so intuitive lectures. And now your professor can help you out whenever you need.

    • @fdsman
      @fdsman 2 роки тому +12

      @@VndNvwYvvSvv I mean I'd personally rather pay to take a test based on these lectures or professor leonard's, seems like 80% of professors at universities are terrible at keeping students engaged.
      IMO if I can basically completely replace your lecture with reading the textbook, why should I bother to show up to lecture?

    • @whatever3041
      @whatever3041 Рік тому +4

      ​@@fdsmanMost students are also terrible these days who got all As in high school and think college is the same.

  • @Mets0311
    @Mets0311 4 роки тому +138

    Wow. I almost didn't recognize you because of the hair. I took an algebra class with you many years ago and now I find myself back here finishing my last differential equations course before completing my CS degree. Still to this day the best professor I've had.

    • @TheMathSorcerer
      @TheMathSorcerer  4 роки тому +63

      Wow Diego!!!!!!!!!!!!!! Long time!!!!!!

    • @meteor8076
      @meteor8076 3 роки тому +3

      cool !

    • @AJAdkins99
      @AJAdkins99 2 роки тому +1

      What school?

    • @carultch
      @carultch Рік тому +3

      What is The Math Sorcerer's real name?

    • @5374seth
      @5374seth Рік тому +12

      @@carultch his real name is Mr. The Math Sorcerer

  • @tedskins
    @tedskins 4 роки тому +32

    I'm an Engineering major and my professor(really a TA) this semester for Diff Eq. is useless with online school. I've been using your videos to help me. Thank you so much

  • @MS-sv1tr
    @MS-sv1tr Рік тому +7

    You're a great lecturer, very engaging and animated. Having recently done some public speaking for the first time in my life I've realized how difficult it really is. You're not just going through material, you're constantly taking the temperature of the group for signs of being lost, trying to learn and remember names, etc. and that's if you can get past the performance anxiety of talking to a group of strangers. Teaching really is a high CPU use activity. I should reach out to some of my professors who made attending lectures enjoyable.

  • @leonardobranco8829
    @leonardobranco8829 4 роки тому +83

    you are an electric teacher, and funny too😂

  • @ec6895
    @ec6895 3 роки тому +20

    Been following since Calc and now I am in DE. You and professor leonard have helped me so much for my engineering major. Literally feel like I took the class with multiple professors everytime. You have no idea how thankful I am :)

  • @liama23
    @liama23 Рік тому +4

    46:25 f(x,y) = some stuff with x und y is probably the best and simplest explanation that i ever heard of.

  • @dzee127
    @dzee127 Рік тому +3

    For every instance when social media is criticized for being the digital crack that it has evolved to be, I will think of this professor and those like him and their content and be grateful that I live in the digital age. Knowledge in this format will basically be preserved in perpetuity and benefit mankind accordingly. Let that sink in for a bit.

    • @Sammysapphira
      @Sammysapphira 2 місяці тому

      So long as youtube maintains this free, yet incredibly expensive library. Download important videos while you still can.

  • @benderbg
    @benderbg Рік тому +2

    I had full math course at my college and I can tell you there was not a single teacher that had 10% of your energy nor enthusiasm. You are the type of teacher that lights up the classroom and for whom students love going back to classes no matter the subject.

  • @aylenegonzalez1928
    @aylenegonzalez1928 4 роки тому +11

    Not a dull moment. I have not studied this in decades. I am getting the hang of it again. Thanks.

  • @jamestrujillo5195
    @jamestrujillo5195 4 роки тому +110

    I learned EVERYTHING in 1 hour. And learned nothing for the past 10 hrs in a week of lecture😂😅. Thx daniel👍

  • @ghadeerzzz5037
    @ghadeerzzz5037 3 роки тому +8

    I love this professor he seem very happy when explaining he really love his job not like others ,wish he teach me ,and thank youuu i really understood it .

  • @Owbly
    @Owbly 4 роки тому +16

    Amazing sir, I have been struggling with taking online classes and my DE grade was terrible. I'm normally a high grade student but online format has made me suffer. Thanks to your lectures on DE, my grade is rising and I'll be able to do good in the course. I appreciate it a lot!!!!

  • @elysiummaybee
    @elysiummaybee 10 місяців тому +1

    Your love of math really give others the enthusiasm to study.
    Thank you for being a great teacher.

  • @Adam_mohammed_
    @Adam_mohammed_ 3 роки тому +2

    OMG!!! incredibly, explicitly comprehensible record ⏺ highly appreciate it... I am currently taking Math 202 and my instructor is Okay.... but I believe this instructor is much more better than any math one had taught me. I am certain that I am going to continue the course with these high quality records. God bless you !

  • @yunyoseb7773
    @yunyoseb7773 3 роки тому +10

    The pandemic has taken me out of the classroom, but this professor made me miss being in one. Really top notch explanations, thanks prof!

  • @makisxatzimixas2372
    @makisxatzimixas2372 Рік тому

    I just want to express my gratitude towards this lecture. You deserve the best for it! I paused the video just to post this comment when you said "I can't solve this. People solve this for a living". This is the context that I have been asking throughout all of my education. Just put the difficulty in context! This is so important. It saved me years of questions and ponder. Thank you!

  • @lifefullofhobbies3802
    @lifefullofhobbies3802 4 роки тому +6

    0 dislikes. Way to go who can dislike this professor? No one.

  • @z0699z
    @z0699z 4 роки тому +3

    He gives me the summary and I like that 😿💕, I don’t know why other teachers doesn’t do that too ... like this is how you should do it don’t repeat what in the book , That shows you don’t even know what is 🔥

  • @太郎田中-i2b
    @太郎田中-i2b Рік тому +2

    Hi, I was in the process of self studying "Introduction to Linear Algebra" by Strang and I've been stuck at section 6.3, "Differential Equations" for about a week now.
    Maybe it's a prerequisite issue, maybe I'm dumb but every line feels like a gigantic logical leap and I was ready to give up on math altogether.
    That's when I found your lecture videos.
    Your clear explanations and dedication to ensuring class comprehension has been incredibly helpful.
    Your energetic and dynamic teaching style keeps me awake despite my focus issues.
    You sir, saved my math career.😤

    • @ILoveMaths07
      @ILoveMaths07 Рік тому +1

      Strang is overrated. He doesn't teach too well.

  • @gustavodelgadillo7758
    @gustavodelgadillo7758 9 місяців тому +1

    carajo mi amigo nunca habia visto un profe tan bueno con tanta pinche energia, eres un crack hechicero de la matematica

  • @LuizaDeARAUJO
    @LuizaDeARAUJO 4 роки тому +6

    I was having a hard time with DEs, but after this very class, it all seemed much more clear
    A M A Z I N G

  • @jessicaoconnor5563
    @jessicaoconnor5563 3 роки тому +1

    Thank you for teaching me what I couldn't learn from my actual professors, you are so passionate about math, you remind me why I became a math major!! I wish I could take your class!!

  • @ecnalms851
    @ecnalms851 11 місяців тому +1

    Love how enthusiastic you are! Great teacher

  • @hepyslepy
    @hepyslepy 5 місяців тому

    I failed calculus on my first year, then found this channel, somehow ive suvived calc 1 and 2.. and now im here,thankyou sir, youre a hero!

  • @jamesjasso6002
    @jamesjasso6002 4 роки тому +6

    The math teacher I've always wanted...
    And now I have!

  • @terencemeikle534
    @terencemeikle534 Рік тому

    I was thinking of taking some time off from mathing for a wee while, but the UA-cam algorithm served me this, and within a minute I was hooked. This is a blast. Love it! ❤️

  • @sarratum
    @sarratum 9 місяців тому

    I want to sincerely thank you for your video lectures and studying tips. I've fallen behind my studies severely due to multiple reasons, the pandemic being the catalyst for making things so much worse. I still try to cope with my failures and defeated mindset. I've been having a hard time as I am unable to attend classes at my university and I am going there only to take exams.Thank you so much for your help. You are giving me guidance with the material, hope and motivation for trying again.

  • @rohanpagapulaan5676
    @rohanpagapulaan5676 Рік тому +1

    love it so much when the professor loves his job and it shows very well

  • @Oznum
    @Oznum Рік тому +1

    Your enthusiasm is contagious! Great class! Awesom problem driven energy. I cant wait watching more of your classes.

  • @ImranMoezKhan
    @ImranMoezKhan 8 місяців тому

    Wow! I watch a lot of your videos when I get time MathSorcerer (esp the book reviews - love those!), but this is the first lecture one I've seen. I would've never guessed you had such a hyped and energetic classroom manner. Very refreshing.

  • @daphney7877
    @daphney7877 4 роки тому +2

    im taking math 1b at uc berkeley and this has really helped me!! i found that after watching your videos, i was really able to test my knowledge and get a+'s on my tests :) thanks!!

  • @phymatoyt7087
    @phymatoyt7087 4 роки тому +6

    I have been struggling in D.E. lectures of my university since the last few weeks, but just one hour of your video(lecture) made things clear and approachable for me. Much love & support from Northeast India ❤️

  • @HeavyMetalShredder
    @HeavyMetalShredder Рік тому +2

    the camera quality is INCREDIBLE. i love how clear the video is and ur explanations actually make sense!

  • @alexisc.villaflor1868
    @alexisc.villaflor1868 4 роки тому +1

    Hi.
    I'm from the Philippines.
    I'd just like to say thank you for your lectures. They are very helpful. Listening to your lectures is also relaxing because you seem really kind teacher.
    Yours is my favorite mathrelated channel.

  • @danslitadventure
    @danslitadventure 8 місяців тому

    I just completed my bachelors last year in computer science. You make me want to go back to major in math! Awesome teaching!

  • @Dascoo77
    @Dascoo77 4 роки тому +2

    I am taking this class and you are bounds better a teacher than my professor. Thank you so much for this! I will be watching this in the next coming week to be super prepared later on in the semester and get an A.

  • @khizraqaiser7299
    @khizraqaiser7299 9 місяців тому

    stumbled across this gem and im glad i did. massive respect for the way of teaching, made it all look so easy.

  • @skyleryoung777
    @skyleryoung777 6 місяців тому

    You may think that no one watches these onsite lecutre videos you've made, professor - you cannot be any more wrong. I absolutely love these videos you've made; they make me feel like I'm one of your students in the class (especially with the cam that follows you around😂)
    Thank you.

  • @KenBilliot-t8b
    @KenBilliot-t8b Рік тому

    A weeks worth of lectures did not get me as far as this hour video. Awesome work!

  • @nokbongadanisa4890
    @nokbongadanisa4890 Рік тому +3

    I haven't started any calculus course but I understood the lecture,you are incredible Sir

  • @samuelgomez9318
    @samuelgomez9318 4 роки тому +1

    Profesor usted es un rifado, gracias por los videos en verdad son de mucha ayuda para todos los que queremos entender al 100 el curso, saludos desde México

    • @TheMathSorcerer
      @TheMathSorcerer  4 роки тому +1

      Saludos! Me alegro que Este video te ayudo👍

  • @JohnFL
    @JohnFL Рік тому +1

    Hello again Math Sorcerer, always great to get your excited perspective that I don't ever get in the classroom. I was especially struggling with the difference between linear and nonlinear D.E.'s so your explanation really helped! I've been sharing your channel with everyone I can that is interested in math because your enthusiasm really rubs off, even if it has been 3 years since the lecture. Keep up the good work:) 🐴

    • @TheMathSorcerer
      @TheMathSorcerer  Рік тому +1

      thank you!

    • @JohnFL
      @JohnFL Рік тому

      @@TheMathSorcerer Also kinda nostalgic that my class is in the exact same room where this was filmed

  • @tvstation8102
    @tvstation8102 2 роки тому +1

    Wow just figured out you have lecture playlists. Just started D/E this week...think I'll follow along with these for an alternate viewpoint as I go. Enjoyed the first one!

  • @nyiawestbrook4269
    @nyiawestbrook4269 11 місяців тому +2

    I love his teaching style🥺

  • @xadir
    @xadir Рік тому

    it's been nearly 15 years since I learned this stuff in my postgrad economics course, and I thought I'd already forgotten it all. I am amazed I still remember :) ODEs, PDEs it's all coming back :)

  • @douglasstrother6584
    @douglasstrother6584 4 роки тому +1

    Without the pressure of seeing Differential Equations for the first time (1982) along with my Physics Courses, watching this it great fun!

    • @TheMathSorcerer
      @TheMathSorcerer  4 роки тому +1

      Wow 1982!! So cool!! Ya it's always way more fun when there is no pressure😁

  • @georgesealy4706
    @georgesealy4706 Рік тому +1

    This is fun. I only took DE about 50 years ago, so I needed a bit of a refresher.

  • @invisiblemango3536
    @invisiblemango3536 10 місяців тому +1

    Wish you were my prof. I've already gone through diff eq, but I came to watch just cause you're so entertaining!

  • @everythingcando132
    @everythingcando132 Рік тому

    I spent lot of time during 2002 by reading books , very difficult in India, few clever students could only understand. Now everyone can attend classes from best teachers. Thanks to the evolution of Technology

  • @SilenceTanki
    @SilenceTanki 5 років тому +3

    27:11 I think it's called family instead of set because a set can't have repeated elements while a family can

  • @tmann986
    @tmann986 2 роки тому +1

    In my diff eq class we are now solving D.E’s that are separable, linear, or exact. I realized i needed to come back to this part of Diff eq to be able to identify wth they are before i can use a technique to solve them haha thank you so much.

  • @larvenkarlsson440
    @larvenkarlsson440 4 роки тому +18

    I love your energy and your humor!!! Is the homework available somewhere? I want to take your course for fun and the challenge!

  • @ezrad5273
    @ezrad5273 6 місяців тому

    It’s a very smart class. When I took DiffEq in my undergrad, half of my classmates were wearing helmets and the other half were chewing their crayons during the lecture.

  • @nirmalakeerthi8684
    @nirmalakeerthi8684 4 роки тому +5

    Great and Every Intresting class to learn D.E .I like the way of Teaching. Thank you very much sir

  • @valor36az
    @valor36az 4 роки тому +2

    I wish I could take your classes. You are so dedicated and enthusiastic. Thanks for posting.

  • @cristofuscolombus1175
    @cristofuscolombus1175 2 роки тому +1

    59:29 How we consider the function of graph without the sketching the graph with derivatiion method,

  • @Master_ofReality
    @Master_ofReality 3 роки тому +2

    This makes me miss college a lot. I graduated over a year ago with an EE degree. I got a pretty good job but I feel like doing graduate studies in applied math. Probably would have to take some remedial courses though (Advanced calc, etc). Wish more universities offered night classes for workers :/

  • @ivansantiagopenaortiz4986
    @ivansantiagopenaortiz4986 3 роки тому

    Why on Earth didn't I find these Lectures before? You are so great, thanks!

  • @joelnaya5341
    @joelnaya5341 Рік тому

    you are such a fun teacher! I see a few empty seats near your desk, plz don't mind if I occupy one of those in one of your lectures😅. I wish my teachers taught me like this. All they did was provide a mathematical definition (which I barely understood and they didn't bother explaining in a simpler way), a few formulas and some practice exercises. No further explanation about how it relates to the past chapters or how are they used in real life etc etc. Recently I started studying maths out of personal interest and sort of a hobby and the first youtube channel I visited was yours. Took your advice and suggestions, revisited the precalculus topics and now I'll be starting with calculus next week.
    Thanks for the motivation!

  • @tomkotch3726
    @tomkotch3726 2 роки тому

    You have become my favorite UA-cam math person!

  • @HmodiKelr
    @HmodiKelr 4 роки тому +1

    It has been an stand-up comedy not just a math lecture .
    Thank you for your work it was very helpful for me.

  • @hayin2041
    @hayin2041 Рік тому +2

    Encouraging professor to average students!!!!!!

  • @mmangalisonxumalo2585
    @mmangalisonxumalo2585 Рік тому

    Wow!! I love mathematics and you sir have just made me fall in love with it all over again

  • @ishajak9452
    @ishajak9452 3 роки тому +1

    Thank you so much for your videos! You make learning Diff EQ so fun!! I've been binge watching your videos all day so far!

  • @buh357
    @buh357 8 місяців тому

    probably the best math teacher on UA-cam.

  • @D.pietertje
    @D.pietertje 9 місяців тому +1

    Wow you really are an Amazing teacher

  • @wesrobertson1889
    @wesrobertson1889 2 роки тому +2

    After watching professor Leonard up to calc 3, your going to teach me the higher math! Thanks. Love your vids
    Edit: Dang, I thought you had a lecture playlist of Real Analysis :(

  • @Kishimita7204
    @Kishimita7204 2 роки тому +2

    Your energy is awesome, math is supposed to be fun

  • @anwaralenazi8879
    @anwaralenazi8879 3 роки тому +1

    I think everyone passes through here should do like and subscribe.. thank you doctor/professor!! I don't know

  • @Pippasaurus
    @Pippasaurus Рік тому +1

    Absolute baller professor. Wish I had this guy

  • @jakeramsay4635
    @jakeramsay4635 4 роки тому +1

    This is the funniest lecture I’ve ever seen. Thanks for teaching me what my actual teacher hasn’t been able to do in over 4 classes

  • @Dr.Pepper001
    @Dr.Pepper001 Рік тому +1

    I used to love solving differential equations in college back in 1970. Now I'm 77 and have forgotten it all...plus calculus, and a lot about algebra.

  • @seamusmoran4776
    @seamusmoran4776 Рік тому

    I just finished calc 2 and im going to take doff eqs and calc 3 next ssummer. Thank you so much for posting these lectures

  • @kimlila-i5r
    @kimlila-i5r 4 місяці тому

    rewatching again for my next semester subject SDE. btw I get A for ODE! thanks a lot cause i watch your videos so many time last semester.

  • @MATHicianPAK
    @MATHicianPAK 2 роки тому +1

    Love his teaching style.

  • @captaingerbil1234
    @captaingerbil1234 3 роки тому +4

    41:20 is the laziest attempt I've ever seen at erasing a board haha. Love your other videos talking about math. I just started a 5 week crash course in DE, so I'll be following this whole series. I appreciate your efforts, Mr. Sorcerer.

  • @Muttheiguhrtn
    @Muttheiguhrtn 4 роки тому

    Awesome and the best professor teaching the subject!

  • @koenth2359
    @koenth2359 8 місяців тому

    3:46 I would not recommend the use of 'del', because it's ambiguous, see Wikipedia:
    The symbol is variously referred to as "partial", "curly d", "funky d", "rounded d", "curved d", "dabba", "number 6 mirrored", or "Jacobi's delta", or as "del" (but this name is also used for the "nabla" symbol ∇). It may also be pronounced simply "dee", "partial dee", "doh", or "die".
    I 'd stick to 'partial' for ∂, and 'nabla' for ∇.

  • @vishalverma5280
    @vishalverma5280 Рік тому

    🎉🎉 you make the laborious task so celebrative 🎉🎉

  • @sihambelmiloud3351
    @sihambelmiloud3351 3 роки тому +1

    The best teachhhher ever ❤

  • @removebeforeflight7365
    @removebeforeflight7365 Рік тому

    This camera system is nice, it’s like being there in class with the other students!

  • @1eyadsg
    @1eyadsg 3 роки тому +2

    I really like you.. I wish that I could be part of your students in the class. They're lucky!

  • @rbresinart
    @rbresinart 2 роки тому

    Good presentation. I can now enjoy O.D.E lecture. Thanks so much

  • @jacobwilson6516
    @jacobwilson6516 3 роки тому

    36:45
    Is it called the Rectangular Hyperbola because it is in a rectangular cartesian coordinate system?

  • @atanusarkar8384
    @atanusarkar8384 3 роки тому +1

    I've been taught that dy/dx is an operator and not a ratio; then, how in Ex-(d) of linear vs non-linear we're dividing equation by dx? Am I missing something here?

  • @koenth2359
    @koenth2359 8 місяців тому

    Rectangular b/c the asymptotes are at right angles.

  • @davidsoto4394
    @davidsoto4394 4 роки тому +1

    You are a good teacher and appear to be passionate about mathematics. If you do not already you should teach one probability course without calculus and one probability course with calculus with the same format you are using in this video. Do you make your lecture notes, practice problem sets, and past exams avalible to the general public for free? My goal with learning about differential equations is just learning how to model things with them. I do not necessarily need to learn how to solve them for my purposes. Thank you so much for these very good videos and for the high quality content you put on your channel.

  • @EconJohnTutor
    @EconJohnTutor 4 роки тому +2

    Hey man, do you have any videos on solving the algebraic riccati equation?

  • @berlianarahmah9664
    @berlianarahmah9664 5 років тому +1

    I am a mathematics education student. Thank you sir for the video. I hope there is a translate into Indonesian. 💕 and i love all your videos sir. ☺

  • @piotr4917
    @piotr4917 4 роки тому +1

    Hi all. I have a question regarding the longest interval of definition. I do understand what it is, I just have a doubt in case of this particular function of y=1/(x^2+c). For the I.C of y(0)=-1 we have selected (-1,1) as the longest interval, however when we plot this function, the 3 parts of the plot are not 3 different functions or 3 different plots, these are all one plot of one particular function y=1/(x^2-1), function that passes through (0,-1) but also all the points from (1,inf) , so shouldn't we choose the right part of the plot as the longest interval? (or the left one of course)?

    • @TheMathSorcerer
      @TheMathSorcerer  4 роки тому

      No you choose the part that passes through the point, that's a requirement in the problem, it has to pass through that point, so the largest interval such that the function passes through that point is (-1, 1).

    • @piotr4917
      @piotr4917 4 роки тому +1

      @@TheMathSorcerer OK, thank you.

  • @ericerpelding2348
    @ericerpelding2348 Рік тому +2

    These lectures are great.
    I am glad you put the whole course here on UA-cam.
    What textbook did you use?

    • @needagoodusername1
      @needagoodusername1 Рік тому

      I second this request ;) I would love to know what textbook, if any, you used in this class. Thank you for the content 🙏.

  • @ngoins2010
    @ngoins2010 Рік тому +1

    Del is not the curly d. Del is the upside down delta, used for the gradient.

  • @chiensyang
    @chiensyang 2 роки тому +1

    I was surprised at the information mentioned (start at 3:39.) I always thought the students must finish Calculus 1, 2, and 3 before taking differential-equations class.

  • @brax300
    @brax300 Рік тому +1

    Watching this as I start my calc journey to get to D.E. Wish me luck.

  • @magnusopump
    @magnusopump Рік тому

    I would hire this guy on the spot!