## Integration of Planck radiation law...

I'm trying to obtain integral of Planck radiation law in Maple:

with this command:

```f := (2*h*(c)^(2))/((x)^(5))*(1)/(exp((h*c)/(x*k*T))-1);
int(f,x=0..infinity);```

but I get some terrible limit that cannot be solved instead of the correct result:

How to obtain correct integral?

planck.mw

## area under pdsolve diagram ...

i want to know the area under a diagram plotted by pdsolve, how can i do that? for example in below , what is the area under p1 diagram?

 > restart:k:=5;
 (1)
 > EQ:=diff(u(x,t),t)=k*diff(u(x,t),x\$2);
 (2)
 > ibc:=u(0,t)=0,u(1,t)=0, u(x,0) = x;
 (3)
 > sol:=pdsolve({EQ},{ibc},numeric);
 (4)
 > p1:=sol:-plot(u,x=0.5,t=0...10,style = line,color = "Blue",legend = "heat Plot",axes=boxed);
 > M:=op(1,op(1,p1));
 (5)
 >
 >
 >
 >

## Evaluating a triple integral...

I am trying to evaluate the following triple integral but it takes much time so i kill the job.

 >
 >

## Evaluating a function containing integral...

I am trying to evaluate the following function for which I am getting a result 0. I just need to make sure the approach as well as result is correct or not. Thanks in advance.

 >
 (1)
 >

## unable to integrate this integral...

I just quickly checked Nasser Abassi 12000.org to see if he's updated it for Maple 2017.  In some areas he has.  I thought I would check one of the integrals that failed for Maple in his tests.  In the Computer Algegbra independent integration tests Maple failed to solve 11.68% of the 3407 integrals in his test while Mathematica only failed 0.88%.  For Maple that seemed quite high, so it is perhaps his method of solving for Maple and perhaps he's more adept with Mathematica.

Here is one of the failed integrals and the single line code he used to solve it.

int((5*x^2+3*(x+exp(x))^(1/3)+exp(x)*(2*x^2+3*x))/x/(x+exp(x))^(1/3),x) # of course because it failed it just spits back the integral.

Can maple solve it?

The answer is supposed to be

## How to integrate a procedure properly?...

I recently encontered a very strange result.

Lets define the procedure:

```Fg := proc(x0,y0)
if (x0>=0)and(x0<=3) and (y0<=x0+2) and (y0>=x0-1) and (y0>=0) and (y0 <=3) then
return y0*(3-y0)*x0*(3-x0)*(x0+2-y0)*(y0-x0+1);
else
return 0;
end if:
end proc:```

The plot looks like needed:

`plot3d('Fg'(x,y), x=0..3, y=0..3);`

But integration returns weird result:

`evalf(Int('Fg'(x,y), [x=0..1, y=0..2.1]));`

7.888753239

`evalf(Int('Fg'(x,y), [x=0..1, y=0..2.2]));`

Error, (in evalf/int) when calling 'Fg'. Received: 'cannot determine if this expression is true or false: 0 <= x and x <= 3 and y <= x+2 and x-1 <= y and 0 <= y and y <= 3'

## fix the Double integrations ...

Fix_integrations.mw

Could you any one help me to fix this application and find the result for integrations?

Many thank,

## finding the area enclosed by a curve such as y=2x ...

Hi, I know the commands for when both curves/functions are y=....., but not when one of them is y=... and the other is a straight line going through the x-axis. I would like to be able to find the points of intersection in decimals, to plot them together such that I can see the points of intersection and finally I need to find he area enclosed between the two. Would appreciate your help.

## How do I get an analytic solution to this integral...

Hello all,

So far I have been unable to find this question anywhere, but I apologize if it is a duplicate. I'm trying to evaluate the integral of sechq(x), where q is a positive integer. Mathematica is able to tell me the result (a hypergeometric function), but for some reason, Maple seems not to be able to compute this integral, it just gives me back the integral. A higher info-level on the 'int' function reveals a line that says 'Risch d.e. has no solution', but I'm not sure if that has anything to do with my problem. Any suggestions or tips on how to get an answer out of Maple would be greatly appreciated!

## How to increase the precision of numerical integra...

I want to calculate the following integral numerically with required precision.

First, the functions are defined:

```G1:=-0.9445379894;
f:= (x) -> 0.9/abs(x-0.4)^(1/3)+0.1/abs(x-0.6)^(1/2);
U1 := unapply(-exp(-x)*(evalf(Int(f(t)*exp(t), t = 0 .. x))+G1)/2-exp(x)*(evalf(Int(f(t)*exp(-t), t = 0 .. x))+G1)/2, x);
U:= unapply(-exp(x)/2*(evalf(Int(f(t)*exp(-t),t=0..x))+G1)+exp(-x)/2*(evalf(Int(f(t)*exp(t),t=0..x))+G1), x);```

Next, I calculate the integral in numerical form:

`evalf(Int(U1(x)^2+U(x)^2-2*f(x)*U(x), x=0..1, digits=4, method = _Gquad));`

If I specify digits=4, Maple return the answer -0.4291

If I use digits=5 or larger, Maple return someting like this

Is it possible to increase precision of calculation?

## Complicated integration from a simple function...

Hey guyz, I am in trouble with calculation attached integral. it is a simple function but a bit long. I can't solve it with maple, Do U have any idea?

intg.mw

## Integral not resolve...

Hi I try this integral:

m2 := int(exp(-(1/2)*z^2)*((exp(B*J*sqrt(q)*z))^2-1)/(sqrt(Pi)*sqrt(2)*((exp(B*J*sqrt(q)*z))^2+1)), z = -infinity .. infinity)

But not resolve.

How can i do?

Regards.

## Is there an efficient way to calculate finite doub...

Dear all,

I would like to evaluate a double integral numerically. The integrand is a complicated function of the variables beta and s, with complex values. The computation lasts for decades without obtaining a result.

I was wondering whether there exists subroutines / methods / tricks that could be helpful to accelerate the integration process. I have attached a Maple script of the double integral of interest. Rough precision would be fine (4 or 5 digits).

Any help would be highly appreciated.

Thanks

Federiko

Question.mw

## integrating a gaussian...

i could have sworn that when itegrating a gaussian maple will write it in terms of the erf functions... but i end up with:

gg:=A * exp( - ( (t - t0) / (tau) )^2 );
val1:=int(gg, t=-x0..x1) assuming t0::real, tau::real, x0<x1, t0>x0, t0<x1, x0::real, x1::real;  #or with no assumptions

the results is just gg unchanged... Doing:

convert(val1, erf)

does not help. I can set t0 (or transform it away), and it works, but I was hoping maple would not require this.

Any thoughts how to help maple with this?

Mathematiaca can read my mind without issues:

## How to determine centre of mass or centre of gravi...

Good evening sir.

I request your valuable support with regard to the above cited query.

With thanks & regards.

Mr.M.Anand

Associate Professor in Mathematics

 1 2 3 4 5 6 7 Last Page 1 of 13
﻿