## stieltjes integral...

How to evaluate a Stieltjes integral ?  I'm not asking for the definition of the Stieltjes integral, I want to know how I can get maple to evaluate one.

## Why do functions with exponential integrals show s...

Hi all,

I am trying to plot in semilog scale a function involving products of exponential integrals and complex exponentials. For small and moderate values of the argument, the plot is well shown. However, for larger values the plot shows strong fluctuations. I was wondering how one can deal with such a problem. Any help is highly appreciated.

Please refer to the attached script for the functio of interest.

Thanks
F

Question.mw

## An not exact differential Equation that I can not ...

Dear All !

I really need to solve this problem as soon as possible, As you know the downside equation is not exact, but I can not find its integration factor, blease help me !

∫{ ( ωx + σy ) d x + (ωy −σx)dy}=0

Regards ,

## Strange integral...

Hi!

Suppose, we need to compute this integral:

int(sqrt(exp(2*I*t)-1),t) from t=0 to t=Pi

If we write this as definite integral, we get right answer: 2*sqrt(2)-(1/2)*ln(17+12*sqrt(2))

But in case of indefinite integral (computing antiderivative) one gets I*arctan(sqrt(exp(2*I*t)-1))-I*sqrt(exp(2*I*t)-1). Substitution t=Pi and t=0 both lead to 0, so we can't transform antiderivative to definite integral. What is the reason?

## How to solve numerically a Fredholm integral equat...

Hi guys,

I am trying to solve a Fredholm equation of the second kind using Maple. An analytical expression cannot be in principle found. I was wondering whether Maple does numerical evaluation of such integral equations. Please see the equation in attach. Any help is highly appreciated.

Thanks

F

Question.mw

## dsolve an indefinite Integral...

Hello all. Is there any solution for the indefinite integralBadIntegral.mw

 (1)

?

Thanks

## how can i use do loop in maple?...

if i m working in maple 13 i have to solve a non linear integral equation then what will be the steps to use the do loop.

## Calculation of indefinite integral...

Hello all,

Is here anyone who could help me with this Integral.

I want to determine P(y=2) in which the Nu is a constant and also is unknown.

In deed I want to derive the P which only has one unknown parameter(Nu). But I cannot solve this indefinite integral although the \alpha_1 , \alpha_2 and B are known constants. The Nu parameter mustn't be valued preferely.Indefinite_INtegral.mw

## How do I solve a simple line integral in Maple?...

Hello there. I have to solve a simple line integral (3*y-x)dL from A(2;1) to B(3;-1). A and B are points in the line described by function y=5-2x. I found a function LineInt. Using paramether Line I wrote LineInt(3*y-x, Line(<2, 1>, <3, -1>)), it doesn't work with error below:

Error, (in Line:-ModuleCopy) invalid input: invalid specification of line

It seems that the problem is with first argument, that is the equation under the integral sign. Or no... How to write it properly? Thanks.

## Numerical integration speed in Maple 18 vs. 2015...

I have recently acquired Maple 2016 and wanted to see how its numerical integration compared to previous version (in this instance, 2015 and 18). This integration is a tougher problem than the usual "textbook" case using a well behaved function. The integrand presented in the worksheet below is a small example but it can get much larger.

I am calculating a triple integral numerically from a function read in from a file which contains Laguerre polynomials. Some simplifications are done first and then that is fed into the integration. In the example script below the input has been put into the program to make it simpler.

So far it appears Maple 18 is faster than 2015 (in this case anyway) and 2016 does not appear to like the syntax I am using even though it runs fine on 18 and 2015 (it does not like the simplify(expr1,LaguerreL) or sqrt parts).

Looking at the stats of the calculation runs:

Maple 18:

memory used=0.52MiB, alloc change=0 bytes, cpu time=20.33s, real time=20.49s, gc time=0ns

Maple 2015:

memory used=350.84KiB, alloc change=0 bytes, cpu time=28.77s, real time=29.24s, gc time=0ns

What is interesting is that Maple 18 is allocating more memory in order to solve the problem compared to 2015. Does anyone have any ideas why this is occuring? Also has there been a syntax change from 2015 -> 2016 which I have not been aware of. Is there a different way to write the script to run in 2016?

Here is the worksheet:

Maple_numeric_speed.mw

- Yeti

## Simple Integral of Product Gives Wrong Results...

Hello,

I've got the following problem: Sometimes when I let Maple compute an integral it gives a result which is much smaller than it should be. This happens even for rather simple integrals such as the product of a Gauss function and a 1/x-type function. Here's a minimal working example:

restart;
with(plots):
f := x -> exp(-x^2):
g := (x,a) -> 1/(1+abs(x-a)):
plot([f(x),g(x,3)],x=-3..10):
for a from 1 to 100 do
A[a] := int(f(x)*g(x,a),x=-infinity..a-1)
end do:
B:=[seq(A[a],a=1..100)]:
X:=[seq(a,a=1..100)]:
plot(X,B);

The plot it returns looks like this:

which is clearly wrong between around a=35 and a=60...

Does anyone have an idea how this can be repaired?

## difficulties evaluating an infinite integral...

Dear Community,

I have difficulties evaluating a rather complicated infinite integral (see attachment). The result should be something like 12.319. Any idea how to go get this?

Tx for the kind help in advance,

best regards

Andras

Infinite_Integral_2.mw

## another problem with integral...

another problem with itegral, again intergal is getting unevaluated answers or folated ( infinity )
what should i do ?

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## problem with integration,which one is correct !?...

hi every one , i have a problem with integration,which one is correct !? also when i remove epsilon option, it returns unevaluated integral . can i have crorrect and reliable answer?

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## Integration in maple...

Hello every one,how do i integrate from this expression?

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