Great job. I just needed a refresher on how to work through this iterative method to find a numerical solution to a circuit problem that I'm working on and this helped oodles.
Why is it that for the 3rd iteration when I do it I get 0.37% for my relative approx. error? I do it just as Ea= [(2.714-2.715)/2.714] * 100 and I get .37%. I double checked with multiple calculators yet I am puzzled as how you got .009%. Can you please explain or anyone do the math at 8:12 in the video and tell me how you got it. Thaks
@dmwirichia You are partially right. You should get 0.037%. The number 0.009% was obtained using more significant digits in the calculations of the roots.
In the Matrix, they showed a clip of some guy doing kung fu. Then Neo said, "I know kung fu." It's like that for your newton raphson video. I know newton raphson method.
@tamilselvi90 That is an initial guess to get the procedure started. To make an estimate of the initial guess, you may look at the physics of the problem. For that, read by going to numericalmethods(dot)eng(dot)usf(dot)edu, click on Newton Raphson Method and see the textbook chapter example.
@numericalmethodsguy my professor says that the root is somewhere where the number sign change like in the bisection method. Example F(-1) = 1, F(-2) = 1.12, F(-3) = 1.04, F(-4) =0.1918, F(-5)=-0.7384...... Then the initial guess for the newton methond would be -4 because it is the number before the f(x) change sign. Is my prof wrong? Pls answer i need to clarify this.
@vitalcoordinates All your prof is trying to do is to start with a good initial guess, and "almost" ensure that you end up finding the root you are looking for. Go to numericalmethods(dot)eng(dot)usf(dot)edu and click on Keyword. Click on Newton Raphson method. Read the N-R method textbook chapter.
@numericalmethodsguy so basically the initial guess closer to zero the better? like in your own function: if x=3 then x^3-20= 7 if x=2 then x^3-20 = -12 ...7 is closer to 0 than -12 so the best initial guess would be 3 along with 2.9 2.88 2.87 etc..? By the way thanks for good references it would help me alot.
@numericalmethodsguy Thank you so much.. hehehe I got the answer by NR and Bisection method but algebraic method confuse me a lot.. but thank you for you reply.. ^_^
@00jklr First all equations to be solved by NR method have to be put in f(x)=0 form (Do you know why). So f(x)=x^2-4*cos(x)=0. f ' (x)=2*x+4*sin(x). So x(i+1)=x(i)-(x(i)^2-4*cos(x(i))/(2*x(i)+4*sin(x(i)))
Read by going to numericalmethods(dot)eng(dot)usf(dot)edu, click on Newton Raphson Method and see the textbook chapter
@IgoruCafekko That is the first derivative of the function f(x)=x^3-20 with respect to x. How did I get that? Go to numericalmethods(dot)eng(dot)usf(dot)edu and click on Keyword. Click on Newton Raphson method. You can also click on Primer on Differentiation if you need brushing up on differential calculus!
@frilink That is an initial guess to get the procedure started. To make an estimate of the initial guess, you may look at the physics of the problem. For that, read by going to numericalmethods(dot)eng(dot)usf(dot)edu, click on Newton Raphson Method and see the textbook chapter example.
@Jodisbear That is an initial guess to get the procedure started. To make an estimate of the initial guess, you may look at the physics of the problem. For that, read by going to numericalmethods(dot)eng(dot)usf(dot)edu, click on Newton Raphson Method and see the textbook chapter example.
thank you sir, actually i didn't attend classes in my college now for finals i dnt know nothing , from u videos i got to know lots of things abt numerical thank u once again
Just wondering why you call this Newton-Raphson. The method being implemented is Newton's method. Newton-Raphson solves systems of non-linear questions by using residuals and a jacobian
@arseneok1 If one knows something about the physics of the problem, that could be used as a basis for an initial guess. Go to numericalmethods(dot)eng(dot)usf(dot)edu and click on Newton Raphson method. Then click on the textbook chapter pdf file and you will see how the physics of the problem is used to assume an initial guess.
sir, can you help me in this question..... i m understand how to solve it.....i solved other questions of N-R method..... but now facing prob in this question.
@AshimHybrid07 Well take the derivative of x^3-x-1, that is 3x^2-1. Now use an initial guess like x0=2 or so in the setup and you are on the way. When the fourth decimal place does not change in the iterations, you have achieved your result. The answer is 1.3247. The eqn has two complex roots too, but those cannot be found by NR method. For that you need to use methods such as Muller's method.
I've also haerd that you can use the newton raphson method combined with the shooting method in order to make your next initial condition guess. Do you have any good resources on how this can be done? I'm attempting it on an assignment. Your lectures are great!
is there neceasary to take seond derivitive in newton rapson mehhod and also assume firtst function to another function let suppose f(x) to g(x) and then take first and second dervitive of this function kindly help me
One only takes first derivative in Newton-Raphson method. There are modifications proposed to the Newton-Raphson method when the equation has repeated roots, which involve taking derivative of f(x)/(f'(x).
That is an initial guess to get the procedure started. To make an estimate of the initial guess, you may look at the physics of the problem. For that, read by going to numericalmethods(dot)eng(dot)usf(dot)edu, click on Newton Raphson Method and see the textbook chapter example.
Thank you for making such a good video. You are much better than my lecturer, I wish I can download your video so that I can watch it over and over again without log in to youtube. Do you have exercises that I can try?
@SnakeEater1912 The exercises are given at the numerical methods website for which the URL is at the numericalmethodsguy channel. Go to keyword, and then to multiple-choice.
I started with 3.0 as an initial guess just to solve the problem. You could start with any guess you want. The root may diverge or converge. In many physical problems, the physics of the problem may help you with a good initial guess.
Example: To find to what depth a ball is floating in water results in a cubic equation. In this case we know that the depth has to be between zero and the value of the diameter of the ball. So choosing half the diameter is a good guess. Do a Google search on STEM numerical methods. Go to the first site that shows up. Click on Keyword. Go to Newton Raphson Method. Click on Textbook notes to see the example.
Great job. I just needed a refresher on how to work through this iterative method to find a numerical solution to a circuit problem that I'm working on and this helped oodles.
frustratedrightnow 4 days ago
This is great. Thank you PAAJI!
SherryZProductions 5 days ago
You explained it very well. Thank you very much!
91418300 1 week ago
Why is it that for the 3rd iteration when I do it I get 0.37% for my relative approx. error? I do it just as Ea= [(2.714-2.715)/2.714] * 100 and I get .37%. I double checked with multiple calculators yet I am puzzled as how you got .009%. Can you please explain or anyone do the math at 8:12 in the video and tell me how you got it. Thaks
dmwirichia 2 weeks ago
@dmwirichia You are partially right. You should get 0.037%. The number 0.009% was obtained using more significant digits in the calculations of the roots.
numericalmethodsguy 2 weeks ago
@numericalmethodsguy TRUE
aljon299792458 1 week ago
This is one "racial" video. =p
leonardphill25 3 weeks ago
In the Matrix, they showed a clip of some guy doing kung fu. Then Neo said, "I know kung fu." It's like that for your newton raphson video. I know newton raphson method.
PolloJack 1 month ago
helping a lot........thank u vry much
abhisheksonu92 1 month ago
thanks for the video.
is the value of x1 correct?
avp9037 2 months ago
@avp9037 It is correct:
3-(3^3-20)/(3*3^2)=2.741
Do you get a different number? If so, let me know!
numericalmethodsguy 2 months ago
find the intersections of 1+.08x=1.04^x using newton.... someone that help me.
ArIGD182 3 months ago
How do u know that initial guess is 3.0? Or can I start with any other value?
tamilselvi90 3 months ago
@tamilselvi90 That is an initial guess to get the procedure started. To make an estimate of the initial guess, you may look at the physics of the problem. For that, read by going to numericalmethods(dot)eng(dot)usf(dot)edu, click on Newton Raphson Method and see the textbook chapter example.
numericalmethodsguy 3 months ago
@numericalmethodsguy thanks a lot! your videos are really useful for me! makes my chemical engineering course more bearable :D
tamilselvi90 3 months ago
@numericalmethodsguy my professor says that the root is somewhere where the number sign change like in the bisection method. Example F(-1) = 1, F(-2) = 1.12, F(-3) = 1.04, F(-4) =0.1918, F(-5)=-0.7384...... Then the initial guess for the newton methond would be -4 because it is the number before the f(x) change sign. Is my prof wrong? Pls answer i need to clarify this.
vitalcoordinates 4 weeks ago
@vitalcoordinates All your prof is trying to do is to start with a good initial guess, and "almost" ensure that you end up finding the root you are looking for. Go to numericalmethods(dot)eng(dot)usf(dot)edu and click on Keyword. Click on Newton Raphson method. Read the N-R method textbook chapter.
numericalmethodsguy 4 weeks ago
@numericalmethodsguy so basically the initial guess closer to zero the better? like in your own function: if x=3 then x^3-20= 7 if x=2 then x^3-20 = -12 ...7 is closer to 0 than -12 so the best initial guess would be 3 along with 2.9 2.88 2.87 etc..? By the way thanks for good references it would help me alot.
vitalcoordinates 4 weeks ago
@tamilselvi90 3 cubed is equal to 21 which is very close to 20. That's why the square root of 20 is guessed to be close to 3
amemoUBC 2 months ago
@numericalmethodsguy Thank you so much.. hehehe I got the answer by NR and Bisection method but algebraic method confuse me a lot.. but thank you for you reply.. ^_^
00jklr 4 months ago
how can you solve this one x^2 = 4cosx using Newton Raphson Method..
00jklr 4 months ago
@00jklr First all equations to be solved by NR method have to be put in f(x)=0 form (Do you know why). So f(x)=x^2-4*cos(x)=0. f ' (x)=2*x+4*sin(x). So x(i+1)=x(i)-(x(i)^2-4*cos(x(i))/(2*x(i)+4*sin(x(i)))
Read by going to numericalmethods(dot)eng(dot)usf(dot)edu, click on Newton Raphson Method and see the textbook chapter
numericalmethodsguy 4 months ago
Comment removed
00jklr 4 months ago
My teacher gave me f(x) = 2x - cos(x), I = [0,1]
what's the derivation of f(x) = 2x - cos(x) ?!
its impossible
IgoruCafekko 4 months ago
@IgoruCafekko You need to find derivative yourself. It is possible.
numericalmethodsguy 4 months ago
@IgoruCafekko f '(x)=2+sin(x)
numericalmethodsguy 4 months ago
@IgoruCafekko
2x -> 2
-cos(x) -> sin(x)
symb09 4 months ago
@symb09 Thanks a lot !!
IgoruCafekko 4 months ago
I didn't get the F'(x) = 3x²
How did you get this result??
IgoruCafekko 4 months ago
@IgoruCafekko That is the first derivative of the function f(x)=x^3-20 with respect to x. How did I get that? Go to numericalmethods(dot)eng(dot)usf(dot)edu and click on Keyword. Click on Newton Raphson method. You can also click on Primer on Differentiation if you need brushing up on differential calculus!
numericalmethodsguy 4 months ago
Great, thanks for the explanation.
hyphens 5 months ago
aaaaannddd where do you get the 3.0 from?????
frilink 5 months ago
@frilink That is an initial guess to get the procedure started. To make an estimate of the initial guess, you may look at the physics of the problem. For that, read by going to numericalmethods(dot)eng(dot)usf(dot)edu, click on Newton Raphson Method and see the textbook chapter example.
numericalmethodsguy 5 months ago
I dont get where you got the 3.0 from at the start. The actual method i can do.
Jodisbear 7 months ago 2
@Jodisbear That is an initial guess to get the procedure started. To make an estimate of the initial guess, you may look at the physics of the problem. For that, read by going to numericalmethods(dot)eng(dot)usf(dot)edu, click on Newton Raphson Method and see the textbook chapter example.
numericalmethodsguy 5 months ago
thank you sir, actually i didn't attend classes in my college now for finals i dnt know nothing , from u videos i got to know lots of things abt numerical thank u once again
Om007able 9 months ago
Just wondering why you call this Newton-Raphson. The method being implemented is Newton's method. Newton-Raphson solves systems of non-linear questions by using residuals and a jacobian
sadowski777 9 months ago
@sadowski777 Newton may even have stolen the idea from Raphson. If it were me, I would call it Raphson method.
numericalmethodsguy 9 months ago
nicely explained . . .
antijames001 1 year ago
better than my proffesor!
kabronponcho 1 year ago
Thank you so much for sharing your knowledge!
duetothefore 1 year ago
Is there any other way of finding initial guesses instead of drawing the graph?
By the way, nice video Sir. I really appreciated it, very easy to understand.
Thanks.
arseneok1 1 year ago
@arseneok1 If one knows something about the physics of the problem, that could be used as a basis for an initial guess. Go to numericalmethods(dot)eng(dot)usf(dot)edu and click on Newton Raphson method. Then click on the textbook chapter pdf file and you will see how the physics of the problem is used to assume an initial guess.
numericalmethodsguy 1 year ago
Very nice! I will aprove my exam =D
batusai005 1 year ago
muy buen ejemplo xD
Gerardithoo 1 year ago
some writing error in the calculation of error. Please check.
bernardengks 1 year ago
THAAAAANK YOU!!!! The vid was INCREDIBLY helpful & NOW i understand the material. MAKE MORE VIDEOS SIR!!!
MHunt95 1 year ago
thank you, that was incredibly helpful!
imvolkan 1 year ago
Nice video teacher!
superboymexicodf 1 year ago
Wat mean by Es?
MachiP0p0 1 year ago
Very helpful, thank you.
hgblb 1 year ago
thanks
tronulu 1 year ago
sir, can you help me in this question..... i m understand how to solve it.....i solved other questions of N-R method..... but now facing prob in this question.
x^3-x-1=0 -four decimal places
AshimHybrid07 1 year ago
@AshimHybrid07 Well take the derivative of x^3-x-1, that is 3x^2-1. Now use an initial guess like x0=2 or so in the setup and you are on the way. When the fourth decimal place does not change in the iterations, you have achieved your result. The answer is 1.3247. The eqn has two complex roots too, but those cannot be found by NR method. For that you need to use methods such as Muller's method.
numericalmethodsguy 1 year ago
I've also haerd that you can use the newton raphson method combined with the shooting method in order to make your next initial condition guess. Do you have any good resources on how this can be done? I'm attempting it on an assignment. Your lectures are great!
fizXgirl314 1 year ago
is there neceasary to take seond derivitive in newton rapson mehhod and also assume firtst function to another function let suppose f(x) to g(x) and then take first and second dervitive of this function kindly help me
tahirsaleem11 1 year ago
One only takes first derivative in Newton-Raphson method. There are modifications proposed to the Newton-Raphson method when the equation has repeated roots, which involve taking derivative of f(x)/(f'(x).
numericalmethodsguy 1 year ago
You are an awesome professor!
whats your background? are u indian or pakistani
thanks once more:)
sahmed28 2 years ago
@sahmed28 Such questions need not be asked. I am a US citizen. Do not let my color, accent or nationality distract you from learning!
numericalmethodsguy 2 years ago
I would like to think he was asking only out of curiosity.
And I'll agree with him, very informative.
Thanks.
AkiThePirate 1 year ago
@numericalmethodsguy AMERICA! YEAH YEAH!
jamescboyd 1 year ago
can anyone tell me wer he got the x0=3.0???
henriettagib 2 years ago
That is an initial guess to get the procedure started. To make an estimate of the initial guess, you may look at the physics of the problem. For that, read by going to numericalmethods(dot)eng(dot)usf(dot)edu, click on Newton Raphson Method and see the textbook chapter example.
numericalmethodsguy 2 years ago
Thank you for making such a good video. You are much better than my lecturer, I wish I can download your video so that I can watch it over and over again without log in to youtube. Do you have exercises that I can try?
SnakeEater1912 2 years ago
@SnakeEater1912 The exercises are given at the numerical methods website for which the URL is at the numericalmethodsguy channel. Go to keyword, and then to multiple-choice.
numericalmethodsguy 1 year ago
Excellent video. Have you done any videos about function interation?
loernIt 2 years ago
Thankyou for making this video
It has helped me!
sneakybadger 2 years ago 2
i dont get 0.009% for the last iteration.
i get 0.037%. Maybe i'm calculating wrongly
mikeymusician 2 years ago 2
You are right. The number 0.009% is obtained using more significant digits in the calculations of the roots.
numericalmethodsguy 2 years ago
@mikeymusician 0.036845983% =D
y3rb4t3ro 1 year ago
Comment removed
lblake58 2 years ago
great instruction. thank you!!
konmak 2 years ago
wow. ur an awesome teacher.
coswominn 2 years ago 2
I've got one question only! Why did you start with 3.0? I mean, why did you choose that value in particular?
elgourmetdotcom 2 years ago
I started with 3.0 as an initial guess just to solve the problem. You could start with any guess you want. The root may diverge or converge. In many physical problems, the physics of the problem may help you with a good initial guess.
numericalmethodsguy 2 years ago
Example: To find to what depth a ball is floating in water results in a cubic equation. In this case we know that the depth has to be between zero and the value of the diameter of the ball. So choosing half the diameter is a good guess. Do a Google search on STEM numerical methods. Go to the first site that shows up. Click on Keyword. Go to Newton Raphson Method. Click on Textbook notes to see the example.
numericalmethodsguy 2 years ago
thanks for uploading this video... u rescue my maths
happysoursop 2 years ago
cheers
dias165 3 years ago
The Best Newton-Raphson method example that I have ever seen. Thank you very much.
mwsc 3 years ago