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#1 Re: Maths Is Fun - Suggestions and Comments » How to add Subscript in the Message Window » 2012-11-29 18:48:10

Oh! I had been trying to put the image from my local drive - it seems, does not work. Thank you very much.

Raabi

#2 Re: Help Me ! » Regula Falsi method Formulae » 2012-11-29 18:43:50

Well, let me explore Secant method, and thanks again for your attention.

#3 Re: Maths Is Fun - Suggestions and Comments » How to add Subscript in the Message Window » 2012-11-29 15:48:29

Thanks for the response. Should I download the image from the laTeX and insert into the message box or Copy & Paste?
I tried both; but could not do it. Would you kindly explain a bit! I tried with the [Img] tag as well, but could not go ahead. Please help.

Regards

#5 Maths Is Fun - Suggestions and Comments » How to add Subscript in the Message Window » 2012-11-29 07:33:44

Raabi
Replies: 5

Hi

I am a newbie in the forum, and may not know certain editing tricks. For example, I am facing a number of problems, like;

-> Entering an equation with Subscripts - for example; x1, x2 ... etc. where 1 and 2 must appear as Subscripts.

-> Is there any way to enter fractions, like; (a + b + c) / d in proper factional format?

-> What does [Img] tag do?

Help will be appreciated.

Raabi

#6 Help Me ! » Regula Falsi method Formulae » 2012-11-29 00:37:56

Raabi
Replies: 4

Hello Wizards

This time, I came up with another confusion on the subject. Just over-viewing the subject, I found two entirely different (apparently, at least) formulae for the method. One is:

x1 = [a * f(b) - b*f(a)] / [f(b) - f(a)]; where a and b are two guess points.

The other is:

x = [xn - x(n-1)] / [f((xn) - f(xn-1)] * f(xn)

Are these two formulae actually the same or different for their use in different situations. Please help keeping in mind that I am just a toddler in this branch of mathematics.

I hope and wish bobbym is somewhere around.

Thanks in anticipation.

Raabi

#7 Re: Help Me ! » Why are we taught solving Numerical methods manually! » 2012-11-23 06:44:53

Got it. Thank you Bobbym for your patience and getting me some confidence. Next time, I may bother you with a better question. Keep smiling.

#8 Re: Help Me ! » Why are we taught solving Numerical methods manually! » 2012-11-23 06:29:14

Yes Bobbym. Actually, I have shot both questions in dark - looking at some example problems. I calculated the Root geometrically, by drawing the curve and then tangents at f(xn) repeatedly (4 iterations only).
I still wonder:

(a)- Couldn't we find the root with classic algebra (Analytically)?
(b)- How to decide which method (Newton's, Bisection, Secant etc) should we use for a particular problem?

Your encouragement really helped me moving ahead. Thank you so much.

Raabi

#9 Re: Help Me ! » How the Numerical methods help with higher Accuracy & Precision » 2012-11-23 06:09:59

I see! We are actually getting redied for a bigger altar.  It is time to run away :-) Thank you Bobbym and have a good time.

#10 Re: Help Me ! » How the Numerical methods help with higher Accuracy & Precision » 2012-11-23 05:55:59

Thanks Bobbym. I got some hint. Some people, like myself, are not good at asking their questions well - I'll try to improve.

Is it one of the main reasons for using Numerical methods, called improved Approximation?

I have some idea on Single Precision & Double Precision Floating Point numbers; but still could not understand; why should we use Numerical methods for the problems; which can be solved with plain algebra (probably called Analytical methods?). A real life example; comparing the two methods may resolve my problem for ever.

I am afraid, you people may feel off for my too basic questions. I can request to bear with me just for a little while; until I start walking, from crawling, on the path of you geeks. Thanks.

#11 Re: Help Me ! » Why are we taught solving Numerical methods manually! » 2012-11-23 02:02:29

This is very encouraging response, Bobbym. Here I have just copied the original question for solution:

Question 1:
Use Newton's Method to find the only real root of the equation

  correct to 9 decimal places.

Question 2:
Use the Newton-Raphson method, with 3 as starting point, to find a fraction that is within 10^−8 of

.
Show that your answer is within 10^−8 of the truth.

I have copied the above questions from the question paper, given in an exam. It will be so nice to get my confusion cleared.

Raabi

#12 Re: Help Me ! » How the Numerical methods help with higher Accuracy & Precision » 2012-11-23 01:41:29

Sorry bobbym, I could not get your point. If it is not inconvenient, please elaborate it to an absolute novice. I want to understand, why and when we take refuge with Numerical methods. The example, I had quoted was for a comparison to understand well.

Raabi

#13 Help Me ! » How the Numerical methods help with higher Accuracy & Precision » 2012-11-22 15:51:30

Raabi
Replies: 8

Hi

As an absolute novice in Numeric Analysis, I have another query - How the Numerical methods (Newton, Euler, Taylor, False Positioning etc.) help with higher Accuracy & Precision.
I mean, if I calculate an equation


with a quality scientific calculator, and then with Newton's method; wouldn't I get the same accuracy to 15 places of decimal, for example? Or, there are some other reasons for using these methods instead of using MS Excel, Scientific calculator, or just Microsoft Math?

Please pardon me for asking too basic questions. They may help me grasp the true essence of the subject.

Thanks in anticipation.

#14 Re: Help Me ! » Why are we taught solving Numerical methods manually! » 2012-11-22 15:30:46

I feel so grateful to Bob Bundy and Bobbym for their help and references. I will try to benefit from these ideas, and wish the best for those; who try to help others like me.

#15 Re: Help Me ! » Why are we taught solving Numerical methods manually! » 2012-11-22 05:18:28

Sorry Bob, I did not see your reply before. Our syllabus, for this semester, is divided into three parts:

Part 1: General Concepts on Computer Science; which include Computer Architecture, Operating Systems and Data Structures etc.
Part 2: System Analysis & Design
Part 3: Numerical Methods. Complete solution of each problem is solved on papers, of course calculator is used just for basic operations.

Each part has a separate paper in the exam. We have already studied Programming in Pascal and C, in our previous semester. So Numerical Methods is an exclusive topic; not just a casual discussion.

Please help.

#16 Re: Help Me ! » Why are we taught solving Numerical methods manually! » 2012-11-22 05:10:51

Thanks for your attention, Agnishom.

I have searched the topic on the Net and found that these methods are taught to be solved manually in US and Europe, as well. On the Web, I found so many questions/answers (solutions) in PDF, for these methods, to help prepare for the college exams, in US and Europe. There is no mention of applying these methods on computers. Then what do they have to do with computer science?

I just want to straighten my perception on the subject; otherwise I will not be able to study it with confused mind.
Further help will be highly appreciated.

#17 Help Me ! » Why are we taught solving Numerical methods manually! » 2012-11-22 04:12:51

Raabi
Replies: 15

Hello geeks

This is my first query and therefore may be too basic. Please, don't ignore it; because I am very much confused and seek help.

I have found a number of chapters on Numerical methods in our Computer Science studies. All the chapters and every problem teaches how to use Newton's method, Taylor Series, Bisection and Secant methods etc for solving questions MANUALLY; like we had been doing all the way till now.

There is no mention of using any of these methods using computers.

I assume, the subject is about using computational methods to solve certain problems; which can not be done manually. Have I wrong perception about Numerical methods? Why are these methods taught in Computer Science?

Would someone(s) be kind enough to clarify my confusion!

#18 Introductions » Hello everybody! » 2012-11-22 03:56:38

Raabi
Replies: 6

Hello everybody!

I have just joined the forum to share (rather just asking for solutions, at this stage :-) points on the Numerical Methods.
Actually, I have just taken Computer Science as an optional subject and found some quite daunting chapters on the subject. It forced me to join the wizards on this forum for some help.

I wish everyone very good time.

Regards,

Raabi Anony

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