#integrate e^(-t/(1-sin(2x))) wrt x from 0 to pi/4

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slender bluff
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[solved] $$\int_0^{\pi/4}e^{-\frac{t}{1-\sin2x}},dx$$

worldly merlinBOT
still gobletBOT
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teaset

slender bluff
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t real positive

waxen vapor
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is that e to the power

slender bluff
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yes

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i have tried the change of variables $u = \frac{t}{1-\sin2x}$ but it led me nowhere

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also tried wolfram alpha / mathematica and the results are series expansions which i am not after

still gobletBOT
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teaset

slender bluff
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which lead me to a more complicated integrand so i did not dig it thru much

queen jewel
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$$ \frac{d}{dt} \left( \int_{a}^{b} h(x,t) , dx \right) = \int_{a}^{b} \frac{\partial}{\partial t} h(x,t) , dx $$

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try this maybe

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the derivative just needs to exist in this case, which it does

still gobletBOT
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Latias

slender bluff
obtuse heart
slender bluff
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no

obtuse heart
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hello hello

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i managed to get the integral to a lapace transform

obtuse heart
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where does this integral come?

slender bluff
obtuse heart
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wait i actually got an idea

obtuse heart
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i want to ask smthing are limits of the integral correct?

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like are they really 0 to pi/4?

obtuse heart
obtuse heart
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only significant things i have uncovered from this integral are the following:

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$$\int_0^{\pi/4}e^{-\frac{n}{2sin^2(x)}}dx$$

still gobletBOT
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T4nuk1

obtuse heart
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from this you can get various integrals each as difficult to evaluate as the last one

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something that came to my mind while doing this were the fourier transforms and fourier functions but the integral limit's don't coincide

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but idk

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it occured to me cus the function is pi periodic

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also

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this came up

obtuse heart
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one can obtain $$1/2\int_0^{\infty}\frac{1}{(x+2)\sqrt{x+1}}e^{-\frac{n(x+2)}{2}}dx$$

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wich is soooo similar to the $$R_C(x,y)$$

still gobletBOT
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T4nuk1

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T4nuk1

obtuse heart
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so for n=0

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one gets that special case

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also if you let $$f(n)=1/2\int_0^{\infty}\frac{1}{(x+2)\sqrt{x+1}}e^{-\frac{n(x+2)}{2}}dx$$

still gobletBOT
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T4nuk1

obtuse heart
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$$\forall n\ge0\ , 0\leq{f(n)}\leq \pi/4$$

still gobletBOT
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T4nuk1

obtuse heart
obtuse heart
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idk it will be kind of hard to actually do this one

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waaaaaaaaaaaaaaait

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i got smthing

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so this can be also seen as the laplace transfor of the derivatice of the arctan(sqrt(x+1))

obtuse heart
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now those limits in the first term change depending on n

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cus on n=0

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that term is just pi/4

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for n aproach to infinity it goes to 0

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and everything in between it goes to -pi/4

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i think

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although i think i saw something similar elsewhere

obtuse heart
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again it would be nice to know from where does this integral comes from

obtuse heart
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uh

slender bluff
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ur math looks ok, haven't thought about integration by parts but still we have this second term

obtuse heart
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idk

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where you got this from

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its so stupidly hard

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:/

slender bluff
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i got it as an intermediate step of something im working on

obtuse heart
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oh

slender bluff
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ig i have to take another route

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thanks

obtuse heart
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what was the og problem

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im curious

slender bluff
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i'll dm u

obtuse heart
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thnksss

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i sent you a friend request

slender bluff
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||"solution" based off of qfunction; use substitution t/(1-sin2x) = x^2 and gradshteyn 4th edition 3.468 1||

slender bluff
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