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You are not logged in. #1 20121008 07:16:10
Integral"(i) Use the substitution x = 2  cosθ to evaluate the integral (ii) Show that, for a < b, where and ." I have done the first part and got which is correct (according to WolframAlpha). But the second part of the question confuses me. I have done this: Let x = (b  a)  cosθ, then dx = sinθdθ and I have ended up with this: but I do not know where to go from here. Help would be appreciated. #2 20121008 07:26:16
Re: IntegralHmm, I am skeptical about that last line. According to WA it is giving me a horrendouslooking solution. #3 20121008 07:29:30
Re: IntegralNever mind, forget WA, it is unable to solve the problem so I do not trust its solution. #4 20121008 07:41:24
Re: 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 20121008 08:06:24
Re: IntegralChecking them now. 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. #7 20121008 11:02:37
Re: IntegralWhere can you get with the substitution x=(ba)a*cos(theta)? Last edited by anonimnystefy (20121008 11:02:52) 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 