Chapter 03.05: Lesson: Secant Method Example

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  • Опубліковано 8 лют 2025
  • Learn via example the secant method of solving a nonlinear equation. For more videos and resources on this topic, please visit nm.mathforcolle...

КОМЕНТАРІ • 111

  • @siddhantraj5323
    @siddhantraj5323 7 років тому +2

    U can't take 4 and 5.5 because I believe for a root to exist, there must be 1 f(-) and f(+) value but f(4.5) and f(5.5) both are positive

    • @numericalmethodsguy
      @numericalmethodsguy  7 років тому +24

      You are confusing secant method and false position method. The false position method (mathforcollege.com/nm/topics/false_position.html , a bracketing method, uses secant lines to estimate the root of an equation. The secant method (nm.mathforcollege.com/topics/secant_method.html , an open method (estimates do not need to bracket the root), uses secant lines to estimate the root of an equation.

    • @RobertoEmilioRomero
      @RobertoEmilioRomero 6 років тому

      Siddi RJ he just did and it worked. Do u have a counterexample?

    • @RobertoEmilioRomero
      @RobertoEmilioRomero 6 років тому +3

      Siddi RJ ur talking about bisection method.

    • @vijayshankar9529
      @vijayshankar9529 5 років тому +1

      both the links are dead...@@numericalmethodsguy

    • @numericalmethodsguy
      @numericalmethodsguy  5 років тому

      @@vijayshankar9529 Please send me the links through this comments section.

  • @silverplasticware
    @silverplasticware 12 років тому +2

    Wow, this was incredibly clear and concise. My professor does not bother giving any examples, so this was very helpful. Thank you very much!

  • @numericalmethodsguy
    @numericalmethodsguy  11 років тому +4

    The secant method is derivable from Newton Raphson method by approximating f '(x(i)) by a backward divided difference approximation. That approximation is the slope of the secant line between points [x(i),f(x(i))] and [x(i-1),f(x(i-1))]. If you doubt that it is secant method, what is it then!

  • @himildesai9898
    @himildesai9898 15 років тому +1

    thanks dude...you saved my life...awesome video...I now understand Secant method so perfectly.

  • @biggbuggy
    @biggbuggy 11 років тому +5

    Mr numericalmethodsguy you are awesome!! Go go professor!!

  • @adrees4u
    @adrees4u 9 місяців тому +1

    is it necessary that x0 be smaller than x1 or is it just a coincidence here? Furthermore how to decide which of the two initial x guess values to be assigned as x0 and x1?

    • @numericalmethodsguy
      @numericalmethodsguy  9 місяців тому

      Not at all. 0 and 1 are subscripts, not a restriction on values of x0 and x1.

    • @adrees4u
      @adrees4u 9 місяців тому +1

      @@numericalmethodsguy Got it. Thank you sir.

  • @SameeKhanSamee
    @SameeKhanSamee 9 років тому +17

    Alhamdulillah, i understood clearly. May Allah bless you

  • @KpopOrigami
    @KpopOrigami 14 років тому +2

    Yay! now i can do my presentation on the Secant method!! thank you so much!

  • @unknownkingdom
    @unknownkingdom 15 років тому +1

    These are very useful videos. Thank you for posting.

  • @JeetKuneDofive
    @JeetKuneDofive 11 років тому +1

    You are amazing you are helping me pass my class.

  • @sunz.6072
    @sunz.6072 7 років тому +1

    Thankyou so much for explaining everything so clearly and so thoroughly without skipping any steps. You videos are so beneficial for me and I recommend them to all my friends. You sir, are an amazing teacher.

    • @numericalmethodsguy
      @numericalmethodsguy  7 років тому

      Thank you.
      To get even more help, subscribe to the numericalmethodsguy channel, and go to MathForCollege.com/nm and MathForCollege.com/ma for more resources and share the link with your friends through social media and email.
      Support the site by buying the textbooks at www.lulu.com/shop/search.ep?keyWords=autar+kaw&type=
      Follow my numerical methods blog at AutarKaw.org. You can also take a free online course at www.canvas.net/?query=numerical%20methods

  • @fizXgirl314
    @fizXgirl314 15 років тому +1

    OH YEAH!! this helped me to find the next guess for use in the shooting method... LOVED IT!

  • @igonesyt
    @igonesyt 12 років тому +1

    Thanks from Brazil! You are awesome.

  • @Itisjustasaganow
    @Itisjustasaganow 5 років тому +2

    This is very helpful, thanks a lot :)

  • @walkingon2001
    @walkingon2001 13 років тому +1

    thank for the video, it is very useful and easy to understand.

  • @erkansenol9891
    @erkansenol9891 11 років тому +6

    Thanks from TURKEY

  • @noora2053
    @noora2053 8 років тому +3

    You are the best !!God bless you ()

  • @AKMautla
    @AKMautla 3 роки тому +1

    beautifully explained. thank you!!

  • @elsbbbb1
    @elsbbbb1 4 роки тому

    you explained everything very clearly , Thank you very much.

  • @whynot13
    @whynot13 14 років тому +1

    I love you ! Cheers from UC San Diego

  • @Letmegoagainplease
    @Letmegoagainplease 11 років тому +1

    Good work sir and thank you, think you can do one for the succesive approximations method?

  • @numericalmethodsguy
    @numericalmethodsguy  11 років тому +2

    It is the same as (a-b) divided by (c-d) is same as (b-a) divided by  (d-c)

  • @numericalmethodsguy
    @numericalmethodsguy  15 років тому +1

    I do not have access to the studio this semester.

  • @lapitburaytitibuday
    @lapitburaytitibuday 15 років тому +1

    dude! do yo have an example on fixed point iteration method? I'm looking around the internet and nothing gives me the exact meaning of it...

  • @etornamtsyawo6407
    @etornamtsyawo6407 5 років тому +1

    how are the initial guesses chosen?

    • @numericalmethodsguy
      @numericalmethodsguy  5 років тому

      These are chosen randomly. If you know the physics of the problem, then that can help. See physical problems here. nm.mathforcollege.com/topics/secant_method.html

  • @numericalmethodsguy
    @numericalmethodsguy  12 років тому

    No, it is not the same. The secant method and regula falsi use the same formula for finding the next estimate of the root, but here is the scoop. The secant method is an open method and hence does not require the two previous estimates to bracket the root; the regula falsi method is a bracketing method and the two previous estimates have to bracket the root in every iteration.

  • @yzchenwei
    @yzchenwei 10 років тому +1

    you suppose to check conditions and swap indexes if necessary.

  • @sunilp63
    @sunilp63 13 років тому +1

    @numericalmethodsguy what abt now??? fixed point...actually my professor dont know how to teach...after I saw ur lectures I became crystal clear...but I still have not understood fixed point and method of false positions..please post some videos..Thanks

  • @brucemendaros8079
    @brucemendaros8079 6 років тому +1

    What is the name of the last process you did where you multiplied it with 100 to get the percentage? Thanks sir have a good day!

    • @numericalmethodsguy
      @numericalmethodsguy  6 років тому

      It is the concept of absolute relative approximate error. See more here. nm.mathforcollege.com/topics/measuring_errors.html

    • @brucemendaros8079
      @brucemendaros8079 6 років тому +1

      Thank you sir, by the way, how did you get the initial values of x0 =4.0 and x1=5.5?

    • @profautarkaw
      @profautarkaw 6 років тому

      @@brucemendaros8079 Those are just guesses which I chose. Generally one uses physics of the problem to get initial guesses but this one is a generic problem.

  • @AnShiKa_sa
    @AnShiKa_sa 5 років тому +1

    I am not able to find any video on fixed point method ...

  • @SANJANASINGH-gp3wh
    @SANJANASINGH-gp3wh 8 років тому +2

    you are so good !!!!

  • @honest_review2492
    @honest_review2492 7 років тому

    thank u so much it really help me alot

  • @zezochi
    @zezochi 12 років тому +1

    thank you very much teacher

  • @benb.1114
    @benb.1114 8 років тому +1

    Thank you very much good sir! :)

  • @deathraiser2820
    @deathraiser2820 10 років тому +5

    how do you choose the inital guesses if they are not given in the question?

    • @numericalmethodsguy
      @numericalmethodsguy  10 років тому +5

      You can use the physics of the problem. Assume you are trying to find the level to which a 3cm radius floating ball is submerged. You could use initial values somewhere between 0 and 6 cm. See example at mathforcollege.com/nm/mws/gen/03nle/mws_gen_nle_txt_secant.pdf

    • @RobertoEmilioRomero
      @RobertoEmilioRomero 6 років тому +1

      Death Raiser best thing to do solving equations like these is to familiarize yourself withe the domain and co-domain AKA range of the function and graph it. Analyze the function. You can also graph them separate in the same viewing rectangles along with different transpositions of the function. At this point you must be familiar how to sketch functions if not graph them using a Computer Algebra System or CAS. There you can visually choose an interval of your choice to begin.

  • @dhananjayalakshan9389
    @dhananjayalakshan9389 4 роки тому

    Thanks a lot sir...

  • @EmeritusG
    @EmeritusG 12 років тому +1

    does this come with free ring dings?

  • @Benerbz8
    @Benerbz8 11 років тому +8

    Your formula has a mistake in it! My textbook reads:
    x(i+1) = xi - f(xi)(xi-1 - xi) divided by f(xi-1) - f(xi)

    • @RobertoEmilioRomero
      @RobertoEmilioRomero 6 років тому +3

      Benerbz8 theres is no mistake. Rearranging the (xi-xi-1) into (xi-1-xi) in the numerator introduces a negative sign. Rearranging f(xi)-f(xi-1) in the denominator into f(xi-1)-f(xi) introduces another negative sign. Both negative signs in numerator and denominator both divide out to + since -÷-=+ . He just has the equation arranged algebraically different but mathematically and graphically identically equal. Simple algebra. Remember (xi-xi-1) = -(xi-1-xi) and f(xi)-f(xi-1) = - [f(xi-1)-f(xi)] . The negative signs introduced in both rearrangements dividie and cancel out to +1. I hope you saw it man. Best. Simple algebra.

    • @RobertoEmilioRomero
      @RobertoEmilioRomero 6 років тому +1

      There is no mistake in his formula. Im guessing you guys who agree he has a mistake in his formula are not very good in catching algebra mistakes or are intermediate level. Any advanced level student would see his equation is the same as the otherguys multiplied by 1.

    • @RobertoEmilioRomero
      @RobertoEmilioRomero 6 років тому +1

      Ur comment was 5 years ago. I hope if u see it now you realized your equation and his are one and the same.

  • @rishav2708
    @rishav2708 14 років тому +1

    thank you so much Sir!!

  • @BilalChaudhary
    @BilalChaudhary 14 років тому +2

    i can not find any video of "regula falsi method" i need that :(

    • @RobertoEmilioRomero
      @RobertoEmilioRomero 6 років тому

      Bilal Chaudhary if you cannot find a specific video. Look for a PDF document of a text related to the topic.

  • @Taiseerghulam2011
    @Taiseerghulam2011 10 років тому +1

    Please sir i need ur help …i am an instructor in LIU... how u re arrange the the formula to get it from the similarity of two triangles ?

    • @numericalmethodsguy
      @numericalmethodsguy  10 років тому

      autarkaw.wordpress.com/2013/10/01/reconciling-secant-method-formulas/

    • @RobertoEmilioRomero
      @RobertoEmilioRomero 6 років тому

      An LIU instructor asking such question? Thats weird.

  • @ramana1-9-7-4
    @ramana1-9-7-4 4 роки тому +1

    Sir p/z explain falsi position method

    • @numericalmethodsguy
      @numericalmethodsguy  4 роки тому

      From my good colleague: nm.mathforcollege.com/chapter-03-06-false-position-method/

  • @Darzs_chidane
    @Darzs_chidane 12 років тому +1

    oh i didn't know that, thanks for clearing that up

  • @LShy3142
    @LShy3142 12 років тому +1

    So how'd you get so smart Buddy?
    Thx for the uploads. Much appreciated. :)

  • @khairulanuar2801
    @khairulanuar2801 9 років тому +2

    Nice video..helped me so much..god bless u

  • @jorge19050
    @jorge19050 14 років тому +1

    very good, thanks!!!

  • @mczairutz01
    @mczairutz01 12 років тому +1

    Thank you Sir. Mabuhay Philippines :)

  • @mreriiie
    @mreriiie 9 років тому +1

    i have y=e^y + ln(y). Answer needs to have 3 correct decimals and i have to use the secant method, how do i proceed?

    • @numericalmethodsguy
      @numericalmethodsguy  9 років тому +1

      +Mr. eriiie Rewrite as f(y)=y-e^y-ln(y)=0. Choose initial guesses and continue iterating till you find 3 decimal places coming out to be same. At any point the guesses cannot be negative as ln(-ve numbers) do not exist within real numbers.

    • @CarlosDominguez-yr1ic
      @CarlosDominguez-yr1ic 8 років тому

      Answer to Mr e. The results of using the secant method with initial guesses y0=0.5 y1=1 with an percent relative error less than 0.0001% is the following for the equation Y-Exp(Y)-ln(Y)=0 using Excel spreadsheet:
      n Yn Error %
      0 0.5 │( x(i+1)-x(i))/x(i+1)│*100
      1 1
      2 0.319604301 212.8869032 (first iteration)
      3 0.351205372 8.997889387 (second iteration)
      4 0.3443491 1.9910818
      5 0.344159898 0.054975036
      6 0.344161287 0.0004037
      7 0.344161287 8.03445E-08
      Best regards from Caracas, Venezuela.

    • @RobertoEmilioRomero
      @RobertoEmilioRomero 6 років тому

      I recommend change x for yor anyother variable of your convenience. The majority of students get intimidated with an equation like yours with Y in it. I will consider doing that first.

    • @RobertoEmilioRomero
      @RobertoEmilioRomero 6 років тому

      I also strongly recommed you try first. Unless you cant do it and admit you dont know how to proceed. Ask someone how to proceed. Never take for granted that you can always ask someone on the internet to do it for you although they mostlikely will do because is fun for them and they know and love to solve problems. You need to be disciplined very well to be a great mathematician. Be realistic and first ask yourself "Am I capable of doing this?" If so never doubt yourself because if others can you can too. One day youll look back at a problem and tell yourself "I cant believe I didn't know how to solve such a relatively easy problem." And qhen I say relatively I mean relative to your age and educational level. Best,

  • @deepeshkushwaha4685
    @deepeshkushwaha4685 6 років тому

    how to calculate an approximate value for (4)(3/4){4 power 3 divided 4} using one step of secant method with x0=3 and x1=2

  • @lapitburaytitibuday
    @lapitburaytitibuday 15 років тому +1

    Fixed point method pls..........

  • @hey_its_zae
    @hey_its_zae 7 років тому +1

    Thank you, sir :)

  • @skunkid2
    @skunkid2 12 років тому +1

    Thank you!

  • @umutert
    @umutert 15 років тому +1

    cool stuff!

  • @saqlainramzan6640
    @saqlainramzan6640 6 років тому

    why 4 cube ?

  • @ozgurerbulan2097
    @ozgurerbulan2097 11 років тому +2

    İngilizcene kurban sağol reyis büyüksün

  • @ashiskumarpanigrahi
    @ashiskumarpanigrahi 4 роки тому

    Plz solve the problem
    Use secant method to find out the root of the equation x3-4x-9 upto 3decimal digits

  • @Sn1perBH
    @Sn1perBH 15 років тому +1

    thx

  • @thtcaribbeanguy
    @thtcaribbeanguy 13 років тому

    i need muller's method!

  • @n.a.4293
    @n.a.4293 7 років тому +1

    thank you

  • @ahmadwaheed2631
    @ahmadwaheed2631 9 років тому +2

    Nice sir

  • @MKStudio-xs6mo
    @MKStudio-xs6mo 9 років тому +1

    how can i contact you sir

  • @badz9308
    @badz9308 8 років тому +1

    thanks

  • @ashandesilva7308
    @ashandesilva7308 11 років тому +1

    thank u soo much :)

  • @Gl0bby
    @Gl0bby 11 років тому

    This is Newtown methode with approximated derivate (instead of accurate one). Really doubt its Secant methode

  • @mrodri63
    @mrodri63 12 років тому +1

    THX

  • @hakkanimim6488
    @hakkanimim6488 6 років тому

    alhamdolliah sir

  • @Darzs_chidane
    @Darzs_chidane 12 років тому

    regula falsi and secant method are the same

  • @rimaljee
    @rimaljee 12 років тому +1

    thnx

  • @Sitonyto
    @Sitonyto 12 років тому +1

    I think your value for X2 is wrong, should have been 3.3553. Well, that's what i got.

  • @Gl0bby
    @Gl0bby 11 років тому

    ohhh, so its basically combination of Euler and Newton Raphson.. that makes sense.. they didnt really need to have a special name for it though

  • @ozgunbzkrt
    @ozgunbzkrt 13 років тому +1

    nice pronunciation..

  • @yubrajkarki.
    @yubrajkarki. 3 роки тому +1

    This is 100% wrong solution and function 4 and function 5.5 can't be taken

    • @numericalmethodsguy
      @numericalmethodsguy  3 роки тому

      You may be confusing secant method and false position method. The false position method (mathforcollege.com/nm/topics/false_position.html , a bracketing method, uses secant lines to estimate the root of an equation. The secant method (nm.mathforcollege.com/topics/secant_method.html , an open method (estimates do not need to bracket the root), uses secant lines to estimate the root of an equation.
      23

  • @JoffreyB
    @JoffreyB 7 років тому +1

    no word about concept where does this formula appeared at all. No graph, no explanation, just stupid using of formula. Dis

    • @numericalmethodsguy
      @numericalmethodsguy  7 років тому

      Look at the link in the description that takes you to all resources in sequence. Better yet, for all resources, see below.
      Subscribe to the numericalmethodsguy channel, and go to MathForCollege.com/nm and MathForCollege.com/ma for more resources and share the link with your friends through social media and email.
      Support the site by buying the textbooks at www.lulu.com/shop/search.ep?keyWords=autar+kaw&type=
      Follow my numerical methods blog at AutarKaw.org. You can also take a free online course at www.canvas.net/?query=numerical%20method

    • @RobertoEmilioRomero
      @RobertoEmilioRomero 6 років тому

      JOFFREY BARATHEON this guy already derived the formula in a prior video.

  • @SchtekarnFU
    @SchtekarnFU 11 років тому +3

    Damnit don't put the point in the center.. makes it look like multiplication

    • @RobertoEmilioRomero
      @RobertoEmilioRomero 6 років тому +1

      SchtekarnFU lol. He puts it there because its understood. If you dont understand it, dont put the . in the center.