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Hi Everybody.

 

Doing some calculation in quantum mechanics, I stuble on that integral:

I see immediately that the answer is 1/2.  But Maple 18 cannot give an answer other than a limit that he cannot evaluate.  I even try assumption that p and hbar are realcons.  I get infinity.

Any idea?

Thank you in advance for your help.

 

--------------------------------------
Mario Lemelin
Maple 18 Ubuntu 13.10 - 64 bits
Maple 18 Win 7 - 64 bits messagerie : mario.lemelin@cgocable.ca téléphone :  (819) 376-0987

The following limit does not return a value. Then the evalf gives a wrong answer.

The answer should be "undefined" or -infinity .. infinity.

limit(exp(n)/(-1)^n, n = infinity) assuming n::posint; evalf(%);


                       /exp(n)              \
                  limit|------, n = infinity|
                       |    n               |
                       \(-1)                /

                               0.

The same happens if you delete the assumption.

 

A similar problem occurs with

limit(sin(Pi/2+2*Pi*n), n = infinity) assuming n::posint;
                            -1 .. 1
without the assumption this would be appropriate.

I've been given a question:

Let pn denote the nth prime number. Then p1 = 2, p2 = 3, p3 = 5, p4 = 7, p5 = 11, . . . .

It is known that the infinite sum 1/p1 + 1/p2 + 1/p3 + · · · + 1/pn + · · · = infinity.

Find the smallest positive integer N so that 1/p1 + 1/p2 +1/p3 + · · · + 1/pN−1 + 1/pN > e. [Hint : ithprime(n) generates the nth prime number.]

How do I start off?

Many thanks!

Would really appreciate the help in doing this question!

Pi= infinity Σ n=0 ((120n^2+An+B)/(16^n(512n^4+1024n^3+712n^2+194n+15))) for some positive integers A,B.

Hint: Set A=0 to find B, then find A.

I'm so clueless as to how to do this. THANK YOU!

Hi,

I'm new to these forums. I'm using Maple 17. What am I missing about the odd behaviour exhibited below? (the code can be copy pasted into Maple)

Suppose I define m,n,p,q as integers and x as real, then define the function h(x,m,n,p,q) below.

assume(m::integer, n::integer, p::integer, q::integer, x::real);
h:=(x,m,n,p,q)->-(1/8*I)*(exp((2*I)*Pi*x)-1)^2*(exp(-(2*I)*Pi*x*(n-q+2))-exp(-(2*I)*Pi*x*(n-q+1)))/(Pi^3*x*(m-x)*(p-x));

If I do:

int(h(x, m, n, p, q), x = -infinity .. infinity)

It says it's 0, but that's not true. The integral is not always 0 but depends on m,n,p,q ... and even Maple acknowledges this. If I do:

int(h(x, 1, 1, 1, 1), x = -infinity .. infinity)

I get -(1/2*I)/Pi ... so clearly not 0.

Also, if I do:

int(h(x, m, n, m, n), x = -infinity .. infinity)

I get -(1/2*I)/(m*Pi) ... again, not 0.

What am I missing? How can I correct this and obtain the analytic expression for int(h(x, m, n, p, q), x = -infinity .. infinity)?

Trying without the assume() causes Maple to run into issues not knowing anything about m,n,p,q.

[ Edit: I finally solved the integral on paper, see my post below if you're curious. The Maple inconsistency and wrong result explained above are still there though ]

Any help would be greatly appreciated.

Regards,

Alex.

Dear Experts,

 

I would like to evaluate the following integral

Integrate(BesselJ(0,x)^2, x=0..Infinity).

 

However, it is not being evaluated in Maple.

 

Appreciate your response.

i'd like to know how type the infinity symbol and other symbols in the integration methods tutor, when i type the word infinity , it says "invalid value, must be a number"

When I use limit like this:limit(LommelS1(4.04, 3.04, z)/z^5.04, z = 0).The maplesoft shows:Float(infinity).How can I deal with this???,Please help me

Dear All,

I am a bigginer of Maple. I'm trying to solve the following in Maple.

 

> with(Statistics);
> f := Distribution(NormalDistribution(0.3,1));

> Y := RandomVariable(f);
> fy := PDF(Y, y);

> Fy := CDF(Y, y);

> int((diff(-ln(1-Fy), y))*fy, y = -infinity .. infinity);

> w := evalf(%);

 

But Maple told me that the answer is the integral -float(∞)..float(∞).

I have added a .mw file showing the problem. I wish to calculate the integral at the bottom of the post. unfortunately the function im using defined at he beginning of the file doesnt behave well for values k larger than 25/30...

The integral I need to evaluate therefore cant be evaluated if one wants to integrate from 0 to Infinity.

Also just integrating till 20 or so is not accurate enough...

Has anybody an idea about better implementation of the problem....

This example was reported to me after a Calculus II student encountered this ridiculous result:

f := (k+5)/sqrt(k^7+k^2):
Int( f, k=1..infinity ):
% = value( % );
/infinity
| k + 5
| -------------- dk = -infinity
| (1/2)
/1 / 7 2\
\k + k /

It found the first four number of this sequence fine but for some reason it wont find the limit as it goes to infinity. I think it should end up being 2sqrt(3)/5 or something like that.

 

Hi,

I'm using Maple to carry out some calculations in Tropical algebra, which requires taking minima of real numbers and infinity.

I'm currently using symbols rather than real numbers, which is causing a problem, I have (for example) the following lines of Maple code:

> assume(0 < a)
> min(a+infinity, 2*a+infinity)
               min(a~ + infinity, 2a~ + infinity)

Dear experts,

 I want to extract the coefficient of z^k from an infinite series summation (known as probability generating function or characteristic function or Z-transformation) , the co-efficient is actually the probability of the R.V. will take value k.

Next problem in the same question is the summation is not working if I sum from 0 to infinity. It is working from 0 to 300.

I have attached the PDF for expressing the problem and the Maple code. I have used convert...

Hi dear friends

 

I want to solve this equation with the foloowing boyndary conditions with maple. please help me to solve it

 

The nonlinear equation is:

 F' ' ' +27*F*F' '=0

And boundary conditions are:

 F' (infinity)=1

 F' (-infinity)=0

 F (-infinity)=0

 

thanks for your attention in advance

 

 

 

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