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You are not logged in. #1 20120127 06:11:29
Linear Interpolation FP1 FormulaIs this formula okay to use for linear interpolation (finding the root of a function in an interval [a,b])? However, in one mark scheme (in a Jan 2007 paper) I saw them use this formula, but with absolute values. Thanks. #2 20120127 06:33:36
Re: Linear Interpolation FP1 FormulaHi; It is reasonably close to a root. You would need the root to be bracketed between a and b. Like all formulas that are derived from theory it sometimes fails laughingly. Try it out on f(x) = x^2 Give it a = 1 and b = 1. In mathematics, you don't understand things. You just get used to them. I have the result, but I do not yet know how to get it. All physicists, and a good many quite respectable mathematicians are contemptuous about proof. #3 20120127 06:51:58
Re: Linear Interpolation FP1 FormulaThanks for the reply. #4 20120127 06:54:06
Re: Linear Interpolation FP1 FormulaSorry for not seeing your f(x) = x^{2} example. #5 20120127 07:08:27
Re: Linear Interpolation FP1 FormulaHi; In mathematics, you don't understand things. You just get used to them. I have the result, but I do not yet know how to get it. All physicists, and a good many quite respectable mathematicians are contemptuous about proof. #6 20120128 08:50:57
Re: Linear Interpolation FP1 FormulaNot sure... I found it on the internet somewhere on some discussion forum so it's probably pretty unreliable because someone could have just made it up without justification. But I figured out the official formula that's accepted; Will probably worry about the derivation until after the exam has finished, as they're not allowed to ask us any proof questions on that topic (only proof by induction questions will come up for series, sequences and proving some function produces some multiple of a number, luckily). Exam is on the morning of 30th Jan, last exam... really want it out of the way. Maths is so boring when you're just doing past papers all the time. #7 20120128 09:24:15
Re: Linear Interpolation FP1 FormulaHi; In mathematics, you don't understand things. You just get used to them. I have the result, but I do not yet know how to get it. All physicists, and a good many quite respectable mathematicians are contemptuous about proof. #8 20120128 19:05:37
Re: Linear Interpolation FP1 FormulaThanks, I will write the rearrangement out in the exam! (after I write the nonrearranged formula out first) #9 20120128 22:53:27
Re: Linear Interpolation FP1 FormulaHi zetafunc.; In mathematics, you don't understand things. You just get used to them. I have the result, but I do not yet know how to get it. All physicists, and a good many quite respectable mathematicians are contemptuous about proof. #10 20120131 07:21:39
Re: Linear Interpolation FP1 FormulaHad the exam today and didn't even need this formula because it didn't come up! Strangely it was an unusually easy paper... I think I got everything correct but there were some slight issues that worried me and may have cost me a couple of marks. One question asked about using NewtonRaphson twice on some function and give the final value to 3 d.p., but didn't know if you should round after doing it the first time. You got the same answer if you rounded or not, though. And then there was plotting complex roots on an Argand diagram... I did them as points not lines! I thought, for example, 1 + i is just the point (1,i), whereas 1 + i is a line joining (0,0) and (1,i). I'm probably wrong, I don't know... #11 20120131 07:23:26
Re: Linear Interpolation FP1 FormulaSounds like you did well. In mathematics, you don't understand things. You just get used to them. I have the result, but I do not yet know how to get it. All physicists, and a good many quite respectable mathematicians are contemptuous about proof. #12 20120131 07:23:32
Re: Linear Interpolation FP1 FormulaHmm, I just checked my FP1 textbook and sometimes they're drawn as dots and sometimes they're drawn as lines... but in the FP2 textbook they're always lines. I think lines might be the correct thing to do, then... looks like I lost a couple of marks. #13 20120131 07:24:39
Re: Linear Interpolation FP1 FormulaI would think they are points and not vectors. In mathematics, you don't understand things. You just get used to them. I have the result, but I do not yet know how to get it. All physicists, and a good many quite respectable mathematicians are contemptuous about proof. #14 20120131 07:28:38
Re: Linear Interpolation FP1 Formula
Ah, that makes sense... thanks. Most people in my class drew lines though. #15 20120131 07:32:14
Re: Linear Interpolation FP1 FormulaWhy will summer be stressful? Summer is a time of barbecues and parties in castles thrown by Dukes and Barons. In mathematics, you don't understand things. You just get used to them. I have the result, but I do not yet know how to get it. All physicists, and a good many quite respectable mathematicians are contemptuous about proof. #16 20120131 07:37:17
Re: Linear Interpolation FP1 Formula
Summer up until midJuly at least. 2 months of exams from midMay to early July (around 22 of them). Then I can take maybe a month off and relax and prepare for the next year. If everything goes to plan I should have 4 exams in Jan 2013 and 2 or 3 in June 2013, which would give me time to just sit back and enjoy maths for a bit rather than train to pass an exam. Then of course there is the issue with this girl in my class but that's something else... anyway. #17 20120131 07:40:03
Re: Linear Interpolation FP1 FormulaThere is always a girl in class to distract you. Nothing can turn a mans mind faster into a big bucket of mush than a girl. In mathematics, you don't understand things. You just get used to them. I have the result, but I do not yet know how to get it. All physicists, and a good many quite respectable mathematicians are contemptuous about proof. #18 20120131 07:41:11
Re: Linear Interpolation FP1 Formula
I suppose... she sits in front of me in all of my exams, literally within touching distance! It's a distraction but I don't mind... #19 20120131 07:43:04
Re: Linear Interpolation FP1 FormulaSame thing happened to me. She was DDG and sat in front me. I guess it is some kind of test that God gives all guys. In mathematics, you don't understand things. You just get used to them. I have the result, but I do not yet know how to get it. All physicists, and a good many quite respectable mathematicians are contemptuous about proof. #20 20120131 07:46:10
Re: Linear Interpolation FP1 Formula
That's the real test we have to pass, I guess... what does DDG stand for? #22 20120131 07:48:36
Re: Linear Interpolation FP1 FormulaDDG means drop dead gorgeous. They start off being a little bit unsure of themselves and cautious the first week or two that they know you are sitting behind them. Trying to figure you out. But as their confidence grows, watchout! In mathematics, you don't understand things. You just get used to them. I have the result, but I do not yet know how to get it. All physicists, and a good many quite respectable mathematicians are contemptuous about proof. #23 20120131 07:54:19
Re: Linear Interpolation FP1 Formulahi zf The limit operator is just an excuse for doing something you know you can't. “It's the subject that nobody knows anything about that we can all talk about!” ― Richard Feynman “Taking a new step, uttering a new word, is what people fear most.” ― Fyodor Dostoyevsky, Crime and Punishment #24 20120131 07:55:56
Re: Linear Interpolation FP1 Formula
Hmm... in the exam hall I sit behind her but in the classroom we're at completely opposite corners... the furthest possible distance apart! #25 20120131 07:58:19
Re: Linear Interpolation FP1 FormulaHi; In mathematics, you don't understand things. You just get used to them. I have the result, but I do not yet know how to get it. All physicists, and a good many quite respectable mathematicians are contemptuous about proof. 