Discussion about math, puzzles, games and fun. Useful symbols: ÷ × ½ √ ∞ ≠ ≤ ≥ ≈ ⇒ ± ∈ Δ θ ∴ ∑ ∫ • π ƒ ¹ ² ³ °
 

You are not logged in. #51 20130806 18:00:15
Re: Change your subject.hi Stefy, So how does the principle value concept work then? Bob You cannot teach a man anything; you can only help him find it within himself..........Galileo Galilei #52 20130806 20:32:13
Re: Change your subject.From complex analysis I think you write the number in polar form, then use De Moivre's theorem to find the principal value, with the angle between π and π (and r is nonnegative). #54 20130806 22:30:22
Re: Change your subject.Does it matter in which sense? 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 #55 20130806 22:50:25
Re: Change your subject.This is a solved example from the book, but has no negative and positive sign in it finall answer though I expect; Last edited by EbenezerSon (20130806 23:04:17) #56 20130806 22:58:19
Re: Change your subject.
If one is not careful, it can lead to incorrect solutions to integrals like the one in #48 (if the method of evaluation is to use a contour with the residue theorem). #57 20130807 08:27:23
Re: Change your subject.
The above is a problem in a book, it is solved in it, but the letter which should be the subject in each case carries a square, and to my suprise the right hand side eqution has no positive and negative sign in front of the root signs and it really baffles me why the signs are absent. #59 20130807 18:03:36
Re: Change your subject.Yes that's fine. #60 20130807 18:15:18
Re: Change your subject.In that case it was not necessary to take a square root at any time. 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. #61 20130807 19:30:38
Re: Change your subject.So you mean there will be no square at the RHS at all? The book has it there. #62 20130807 19:44:36
Re: Change your subject.
You said the subject is squared. I took your quote to mean you wanted to solve for U^2. If you want to solve for U then we will take a root. 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. #63 20130808 22:14:19
Re: Change your subject.But if I am solving for U, and take root of both sides, I think there will come a root sign to the the R.H.S, in front of the root sign there must be positive and negative sign present, is that not it? #64 20130808 22:15:31
Re: Change your subject.Yes, if you solve for U, then there will be a ± in front. 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. #65 20130808 22:23:02
Re: Change your subject.Thanks, Bobbym #66 20130808 22:27:34
Re: Change your subject.It just means one is positive and the other is negative. 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. #67 20130809 18:58:24
Re: Change your subject.It seems you did not get what I mean. #68 20130809 21:57:33
Re: Change your subject.Because sometimes it is left out. 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. #69 20130811 01:49:45
Re: Change your subject.If for inÅŸtance, a student does that would not a teacher mark him down? #70 20130811 02:08:30
Re: Change your subject.Yes he/she might mark them down. 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. #71 20130811 02:33:30
Re: Change your subject.Thanks. #72 20130811 02:38:34
Re: Change your subject.When dealing with the Pythagorean theorem you are usually working on a triangle. Triangles can not have negative lengths. 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. #73 20130812 00:18:15
Re: Change your subject.Okay, Thanks bobbym. #74 20130812 00:34:23
Re: Change your subject.Speed is a scalar, so it can not be negative. Velocity is a vector, it can be negative. According to the physicists, time can take a negative value. 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. #75 20130812 05:03:01
Re: Change your subject.On what basis can time take a negative value? 