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You are not logged in. #1 20120722 13:46:41
Evaluate this integralThis integral comes from trying to get the surface area of y=1/x rotated about the xaxis. Good luck! It's a toughie. The eclipses from Algol (an eclipsing binary star) come further apart in time when the Earth is moving away from Algol and closer together in time when the Earth is moving towards Algol, thereby proving that the speed of light is variable and that Einstein's Special Theory of Relativity is wrong. #2 20120723 13:55:12
Re: Evaluate this integralProblems of this nature (integrals obtained by rotation as mentioned) if they are amenable to integral tables or substitution methods are usually highly rigged. Rotation problems like this with just any old function f(x) usually generate horrendous integrands not amenable to elementary methods. Writing "pretty" math (two dimensional) is easier to read and grasp than LaTex (one dimensional). LaTex is like painting on many strips of paper and then stacking them to see what picture they make. #3 20120723 16:35:22
Re: Evaluate this integralHi Fruityloop; 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. #4 20120723 22:09:44
Re: Evaluate this integralHi bobbym 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 #5 20120724 04:10:40
Re: Evaluate this integralHi; 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 20120724 04:27:19
Re: Evaluate this integralSorry, mybad. I forgot the substitution of differentials. 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 #7 20120724 04:30:26
Re: Evaluate this integralThat is okay. 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 20120724 04:39:26
Re: Evaluate this integralWhat does M spit out for the integral? 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 #9 20120724 04:40:16
Re: Evaluate this integralThe wrong answer! 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 20120724 04:41:39
Re: Evaluate this integralCan you post it? I am interested to see what it is because you suggested using it. 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 #11 20120724 04:44:49
Re: Evaluate this integralI hesitate to put his ugly solution that is magic next to mine. 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 20120724 04:48:02
Re: Evaluate this integralHi bobbym 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 #13 20120724 04:51:44
Re: Evaluate this integralHi; 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 20120724 05:02:59
Re: Evaluate this integralDo the integral in Wolfram and click show steps. Interesting behaviour. 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 #15 20120724 05:04:55
Re: Evaluate this integralYes, that is what he gets. When I follow along the answer is different. Also it has a complex fungus attached to it! 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 20120724 05:13:20
Re: Evaluate this integralYes, the answer is different from what he gets in the "Show steps" solution! But I do not see any complex stuff. 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 #17 20120724 05:18:05
Re: Evaluate this integralDid you work towards the solution using M? You will get the wrong answer. 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 20120724 05:28:34
Re: Evaluate this integralWolfram spits out the wrong answer. 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 #19 20120724 05:34:00
Re: Evaluate this integralIs that a question? The package and Alpha are not the same thing. He gets the wrong answer on the integral because of the partial fraction decomposition. When I plug in x =1. he spit out a complex number! 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 20120724 05:38:56
Re: Evaluate this integralBut I don't have M. 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 #21 20120724 05:46:52
Re: Evaluate this integralWell, then why did you want to see what it did? 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. #22 20120724 07:07:29
Re: Evaluate this integralhi bobbym, Writing "pretty" math (two dimensional) is easier to read and grasp than LaTex (one dimensional). LaTex is like painting on many strips of paper and then stacking them to see what picture they make. #23 20120724 07:25:46
Re: Evaluate this integralProbably is. 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 20120724 07:55:43
Re: Evaluate this integralHi noelevans; 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. #25 20120724 08:05:07
Re: Evaluate this integralMinor error compared to M's. Speaking of it, are you going to feedback them to llet them know about it? 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 