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What is the integral of f'(x)=sin((7*x^3)/(2*x^(-2)))^(-2) with respect to x? You need not post how to do the solution, unless you want to be super helpful. I've gotten a lot of different answers, and someone told me that there's some gamma thing going on and branch cuts in the complex z plane and this wierd stuff.

2006-12-28 22:11:19 · 5 answers · asked by Sean 2 in Science & Mathematics Mathematics

I don't know why it did the ... in the question, I clearly put -2 but it should be csc^2.

2006-12-28 22:56:04 · update #1

That last extension might not have been very clear. I'm looking for ∫csc[(7*x^3)/(2*x^[-2])]^2 dx.

I don't think this will be easy to solve by hand, I'd use mathmatica, but the computer with that on it is several hundred miles away.

2006-12-29 00:43:01 · update #2

This also seems to be too difficult to solve with web-based integration websites.

2006-12-29 01:22:37 · update #3

5 answers

It's definitely nonelementary.
First, simplify the inside to get
∫ csc^2(7/2*x^5)dx
Now let u = 7/2 x^5
dx = Cu^(-4/5) du,
where C = (2/7)^(1/5)*1/5.
Finally integrate by parts. I'll leave out the gory details,
but it boils down to integrating
∫u^(-9/5)cot u du,
and here we reach a dead end.
There seems to be no way to calculate this
last integral. Sorry!

2006-12-29 06:55:59 · answer #1 · answered by steiner1745 7 · 0 0

cos(2x) = 1 - 2 sin^2(x) Therefore cos(2 * 3/4 x) = 1 - 2 sin^2(3/4 x) cos(3/2 x) = 1 - 2 sin^2(3/4 x) 2 sin^2(3/4 x) = 1 - cos(3/2 x) sin^2(3/4 x) = 1/2 - (1/2) * cos(3/2 x)] The integral = x/2 - (1/2) * (2/3) * sin(3/2 x) + C = x/2 - (1/3) * sin(3/2 x) + C (where C is constant of integration)

2016-03-28 23:29:05 · answer #2 · answered by Anonymous · 0 0

BRO. the answer is a bit critical what i can help you out is by telling you a way to solve the ques. what you need to do is to use a formula i.e. ( U.V ) or
U x ∫ V d dx - ∫ ( U d x V ) dx
dx dx

where U is your actual question and V is 1

2006-12-29 00:32:45 · answer #3 · answered by Abbi 1 · 0 0

You're making to work my brain, jejeje. I'm trying to do it via complex integration but I can't find the solution yet. I'll keep trying.

2006-12-28 22:53:51 · answer #4 · answered by j_orduna 2 · 0 0

hello
any integration problem you want to solve heres a free link that solves everysingle impossible integrals

http://integrals.wolfram.com/index.jsp

2006-12-29 01:20:22 · answer #5 · answered by Mostafa Hammouda 1 · 0 0

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