Integrating using t=tan(x/2) substitution - [The Weierstrass substitution]

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  • Опубликовано: 21 авг 2024
  • In this video, I showed how to integrate a function of the form 1/(c + bsinx +acosx) .

Комментарии • 63

  • @jan-willemreens9010
    @jan-willemreens9010 Год назад +30

    ... Newton, what I forgot to say is, keep doing your presentations on the blackboard with just a simple piece of chalk, your handwriting is excellent for this! Jan-W

  • @kinyerajoel9731
    @kinyerajoel9731 Месяц назад

    I am a teacher, but whenever I watch your video, everything is just fine to teach

  • @dusscode
    @dusscode 10 месяцев назад +9

    You can actually solve it much more simply by multiplying the numerator and denominator by the conjugate of the denominator, to get ∫ (1-sin(x))/cos^2(x) dx.

    • @Koolasuchus8
      @Koolasuchus8 7 месяцев назад +2

      Yeah but this method is very very useful for integrals that are impossible to figure out using other methods without already knowing the answer and working back. Its hard to explain but the "t method" is a very useful tool that some rusty person could use to solve integrals he is unprepared for or cant see the shortcut. Put simply its inductive not deductive. This is an easy example of the t rule.

  • @boydbanda1912
    @boydbanda1912 Год назад +10

    Big man you're doing it more than anyone. I like the way you Tutor us. Keep up the good work manh.

    • @PrimeNewtons
      @PrimeNewtons  Год назад +1

      Thank you. Your comment sounds African 😀. Where are you from?

  • @robread-jones3698
    @robread-jones3698 Год назад +14

    Thanks Newton, that was so good. I really enjoyed that.
    Keep up the great videos.
    👍

    • @Ni999
      @Ni999 Год назад +2

      Same here. 👍

  • @willwill3917
    @willwill3917 3 месяца назад +2

    you are a perfect teacher, moreover a perfect human

  • @user-ej1sk7zm3j
    @user-ej1sk7zm3j 6 месяцев назад +3

    Newton.. sincerely speaking you have helped me alot..🙏

    • @PrimeNewtons
      @PrimeNewtons  6 месяцев назад

      Glad to hear that

    • @user-ej1sk7zm3j
      @user-ej1sk7zm3j 6 месяцев назад

      @@PrimeNewtons thank u..I'm a Kenyan student

  • @romanmuller997
    @romanmuller997 Месяц назад

    Wow, this is a great video. You have such an excitement inducing voice. You're really getting the beauty of maths across.

  • @halimsemihozcan8526
    @halimsemihozcan8526 2 месяца назад +1

    Thanks for this lesson . You are a good teacher .

  • @utuberaj60
    @utuberaj60 Год назад +3

    Nice way to get the answer.
    But Mr Newton, I did it WITHOUT any substitution.
    In fact all I did was multiply and divide by the conjugate of the DENOMINATOR ( 1 - Sin X) and there onwards ,it is quite simple really for a good Calc 1 or Calc 2 level student.
    Your method, though a nice U-sub, seems quite lengthy, if I may say, Mr Newton.
    To make this a little harder, why not try to solve the same Integral as a DEFINITE integral from 0 to pi/2? It is quite an interesting one indeed, trust me❤❤

    • @PrimeNewtons
      @PrimeNewtons  Год назад

      I'll give it a shot soon

    • @mehakghous7884
      @mehakghous7884 9 месяцев назад

      Well for your information "SIR", this method (sir newton's one) really saved me since i had to do the integration USING this method in my calculus paper. Although your method is right, i guess your knowledge has made you arrogant, and you are trying hard to prove your supremacy to everyone by spreading hatred on the internet, and i guess that's why you're not teaching here with thousands of subscribers. have a great day "❤❤❤❤"

  • @georgesadler7830
    @georgesadler7830 10 месяцев назад +1

    Professor Prime Newtons, thank you for the video. Calculus Two playlist on RUclips does not cover this topic. This topic is called special substitution, which is part of Techniques of Integration in Calculus Two. This is an error free video/lecture on RUclips TV with Professor Prime Newtons.

  • @paulmatthewduffy
    @paulmatthewduffy 7 месяцев назад +1

    Excellent refresher. Thank you.

  • @ndzalamankwinika2999
    @ndzalamankwinika2999 10 месяцев назад

    You are a good teacher, sir

  • @senayurekyakan2248
    @senayurekyakan2248 5 месяцев назад

    best teacher ever

  • @mb-hv6kf
    @mb-hv6kf 2 месяца назад

    Thank you for the nice example and exposition. Added another tool to the toolkit.

  • @kurtecaranum3047
    @kurtecaranum3047 3 месяца назад

    If you remember all your derivatives, the integral could be solved as
    (1 - sin x)/(cos^2 x) dx
    (sec^2 x - sec x tan x) dx
    tan x - sec x + C

  • @_vblax
    @_vblax 4 месяца назад

    life saver! great explanation, thank you!

  • @estevaocachiliva3249
    @estevaocachiliva3249 2 месяца назад

    Great video professor👏🏽
    I have two questions:
    1 - can I use this t substituion whenever I have a integral of cosine and sine? And if I have another trigonometric identity can I rewrite this identity in terms of sine or cossine or both to apply this substituion?
    2 - how can I apply this substituion in those cases I have in the answer a angle in radians summing the variable on the argument of some trigonometric identity. Like for exemplo how to apply t substituion on the integral of dx/ sen(x) + cos(x).
    The answer of this integral is 1/sqrt 2 that multiply ln( csc( x + pi/4) - cot( x + pi/ 4)
    How can I reach the same result with t substituion.

  • @mikedavis7636
    @mikedavis7636 9 месяцев назад +2

    I multiplied the numerator and denominator by the conjugate, 1 - sin X, got 1 - sin x/1-sin²X, substituted Cos²X for 1-sin²X, split the fraction, took the integral and ended up with tan x - sec X + c

    • @theandrewadler
      @theandrewadler 8 месяцев назад

      That's really smart. Good job

    • @hazwi
      @hazwi 7 месяцев назад +1

      i did the exact same process

  • @joseantonioandrade2808
    @joseantonioandrade2808 2 месяца назад

    Newton you can also solve that integral using the conjugate of 1+sinx , that is multiplying up and the bottom by 1- sinx, and the final result is tanx-secx, just another way to do it. greetings

  • @jan-willemreens9010
    @jan-willemreens9010 Год назад +4

    ... A good day to you Newton, Right out of one of my " old and trusted " little math notebooks regarding integrals the following solution path in short: Given INT(1/(1 + sin(x))dx [ multiply top and bottom of the integrand by (1 - sin(x)) ] --> INT((1 - sin(x))/(1 - sin^2(x)))dx = INT((1 - sin(x))/cos^2(x))dx = INT(1/cos^2(x))dx + INT(- sin(x)/cos^2(x))dx [ u = cos(x) --> du = - sin(x)dx ] = INT(sec^2(x))dx + INT(1/u^2)du = tan(x) + INT(u^-2)du [ applying the good old REVERSE power rule, remember Newton? (lol) ] = tan(x) - 1/u [ u = cos(x) ] = tan(x) - 1/cos(x) + C = tan(x) - sec(x) + C = (sin(x) - 1)/cos(x) + C ... etc etc ... I leave the outcome to everyone's preference ... Thank you too Newton for your great performance; I really mean this, an eye opener for me; isn't it called the Weierstrass method? A pleasant weekend to you, Jan-W

    • @PrimeNewtons
      @PrimeNewtons  Год назад +1

      Yes! This is an alternative. I call it 'rationalization'. I just get scared with the integral of secx or sec²x or sec³x. They scare me. But certainly, in recent times I have used that until I found my old Engineering Math book by K. A. Stroud. Then it all came back to me. We are dealing with the cold and rains here. It's never been like this before. Now I appreciate sunshine 🌞. And thank you for helping with the name. Truly it's called the Weierstrass Substitution

  • @sssoup
    @sssoup 2 месяца назад

    Excellent !

  • @arungosavi5698
    @arungosavi5698 7 месяцев назад

    Brilliant way to solve sir

  • @swarnabhamitra7233
    @swarnabhamitra7233 7 месяцев назад

    Just use sinx=(2tan(x/2)) /(1+tan^2(x/2) ) =(2tan(x/2)) /(sec^2(x/2)) it becomes simple by half and double angles relations

  • @stevemwanza7521
    @stevemwanza7521 Год назад

    Clearly explained 👏👏 Thanks

  • @UKPEINDANIELU.
    @UKPEINDANIELU. 25 дней назад

    Fantastic

  • @levisim997
    @levisim997 Год назад +1

    Very helpful! ❤

  • @RaadoNoori-km5ej
    @RaadoNoori-km5ej 2 месяца назад

    That is great, but I have question could we use t= tanx
    Or we have to make angle x/2

  • @erms_234
    @erms_234 3 месяца назад

    amazing

  • @chappel9998
    @chappel9998 7 месяцев назад

    Amazing video. You are so damn smart.

  • @fortunateonka
    @fortunateonka 10 месяцев назад

    Well explained sir❤

  • @ThenSaidHeUntoThem
    @ThenSaidHeUntoThem Год назад +1

    Thank you! 😊

  • @adebayoisraeladeshola
    @adebayoisraeladeshola Месяц назад

    Thanks sir

  • @lunaresting
    @lunaresting Год назад +1

    Thanks a lot man

  • @Bulbo_215
    @Bulbo_215 7 месяцев назад

    Loved it

  • @split9853
    @split9853 4 месяца назад +1

    How come the day after ive had my calculus 2 exam this video gets recomended 😒

  • @EE-Spectrum
    @EE-Spectrum 4 месяца назад

    Is there a relationship between t-substitution and the half-angle identities?

  • @TSR1942
    @TSR1942 7 месяцев назад

    Try by multiplying the denominator and numerator with conugate.

  • @adebayoisraeladeshola
    @adebayoisraeladeshola Месяц назад

    What if there are
    non linear function

  • @VENOMx007x
    @VENOMx007x 10 месяцев назад

    Sir you also do it by substituting sinx with 2tanx/2 upon 1+tan square x/2

  • @deborahatobrah6827
    @deborahatobrah6827 4 месяца назад

    I like u boss

  • @domanicmarcus2176
    @domanicmarcus2176 7 месяцев назад

    Why did you choose x over 2 and not just Theta?

    • @PrimeNewtons
      @PrimeNewtons  7 месяцев назад

      That's the substitution that works

  • @d.yousefsobh7010
    @d.yousefsobh7010 8 месяцев назад

    Sir you also do it by substituting 1+sinx=

  • @domanicmarcus2176
    @domanicmarcus2176 9 месяцев назад

    Can we go backward? We now that sin^2(x)+cos^2(x) =1. Can we sub sin^2(x)+cos^2(x) for 1 and then separate our fractions like this: sin^2(x)/(1+sin(x)) +cos^2(x)/(1+sin(x)) and then keep manipulating our algebra to solve the problem in the video? Please let me know if it is possible? Thank You

  • @chuckc3665
    @chuckc3665 5 месяцев назад

    this is a very bad method, you should trig identities

  • @jusajiggynigga2524
    @jusajiggynigga2524 Год назад +1

    love your content bro

  • @electricitysexenergy1509
    @electricitysexenergy1509 Год назад

    Which level sir