Items tagged with integral

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I need to calculate the following complex integral:

oint_C { [(z^4exp(2z)+1)/(z+i)^3] - [(z^3+z)/{(z-2i)(z-5)}] + 8*Pi*exp } dz,

 

Where C is the circumference |z-1| = sqrt(11/2), positively oriented.

 

Someone can help me, I already researched but I can not integrate.

3.mw

There are 2 questions actually. The first as the title says is about taking the integral. I have 2 functions that were found numerically from the system of differential equations (see the file), and I need to take the integral of the expression that includes both of them. Maple gives me something like Int () = Int (), so it doesn't solve anything. Why can it be?

The second question is about varying the boundary conditions. If, for example, I have the system with the condition like R(x_0)=R_0, can I get the plot  of R(x,R_0)? In my case I need to vary conditions on R and mu (R(0)=R_0 and mu(0)=mu_0) and then get the plot of the integral in relation to R_0 and mu_0. Is it even possible?

Can someone answer why i get Float(undefined) while computing integral

Here is my example

NULL

restart

with(plots):

NULL

alpha0 := .3;

.3

(1)

R := .1;

.1

(2)

sigma := 636;

636

(3)

Kfc := 101;

101

(4)

Ksc := 9;

9

(5)

E := 2*10^5;

200000

(6)

`δth` := 2*10^(-7);

1/5000000

(7)

`δc` := 0.8e-1*10^(-3);

0.8000000000e-4

(8)

p := 400;

400

(9)

`lδz` := 12.1*10^(-3);

0.1210000000e-1

(10)

lKz := 20.3*10^(-3);

0.2030000000e-1

(11)

eta := 10^(-5);

1/100000

(12)

l0 := 0;

0

(13)

xi := p/sigma;

100/159

(14)

KImax := evalf(p*sqrt(Pi*l));

708.9815404*l^(1/2)

(15)

``

`Nδ` := evalf(E*sigma*(int((-xi^2+1)*(-KImax^2+Kfc^2)/((KImax^2-Ksc^2)*((-R^4+1)*(KImax^2+Ksc^2)+eta*E*sigma)), l = l0 .. `lδz`))/alpha0);

Float(undefined)

(16)

``

NULL

NULL

NULL

NULL

NULL

``

``

``

``

``

NULL

NULL


 

Download N.mw

Thanks in advance

Good day!

As part of an exercise I've calculated the length of a hypotrochoid numerically. To check my result I repeated the calculation in Maple, but received a different result. When double checking using WolframAlpha I got the same result as with my numerics. Maybe someone of you can tell me where I made a mistake.

Thanks in advance.
Sören


Link to WolframAlpha calculation: http://www.wolframalpha.com/input/?i=x%28t%29+%3D+%281-0.6%29+cos%28t%29+%2B+0.8+cos+%28+%281-0.6%29%2F0.6+*+t%29,+y%28t%29+%3D+%281-0.6%29+sin%28t%29+-+0.8+sin+%28+%281-0.6%29%2F0.6+*+t%29+from+t%3D0+to+6*pi

restart; with(VectorCalculus)

R := 1;

1

 

.6

 

.8

(1)

x := proc (t) options operator, arrow; (R-r)*cos(t)+d*cos((R-r)*t/r) end proc:

y := proc (t) options operator, arrow; (R-r)*sin(t)-d*sin((R-r)*t/r) end proc:

plot([x(t), y(t), t = 0 .. VectorCalculus:-`*`(6, Pi)]);

 

ArcLength(`<,>`(x(t), y(t)), t = 0 .. VectorCalculus:-`*`(6, Pi))

12.67823876+0.*I

(2)

diff(x(t), t);

-.4*sin(t)-.5333333334*sin(.6666666668*t)

(3)

diff(y(t), t)

.4*cos(t)-.5333333334*cos(.6666666668*t)

(4)

sqrt(VectorCalculus:-`+`((-.4*sin(t)-.5333333334*sin(.6666666668*t))^2, (.4*cos(t)-.5333333334*cos(.6666666668*t))^2))

((-.4*sin(t)-.5333333334*sin(.6666666668*t))^2+(.4*cos(t)-.5333333334*cos(.6666666668*t))^2)^(1/2)

(5)

simplify(((-.4*sin(t)-.5333333334*sin(.6666666668*t))^2+(.4*cos(t)-.5333333334*cos(.6666666668*t))^2)^(1/2))

(.4444444445+.4266666668*sin(t)*sin(.6666666668*t)-.4266666668*cos(t)*cos(.6666666668*t))^(1/2)

(6)

int(((-.4*sin(t)-.5333333334*sin(.6666666668*t))^2+(.4*cos(t)-.5333333334*cos(.6666666668*t))^2)^(1/2), t = 0 .. VectorCalculus:-`*`(6, Pi))

12.67823876+0.*I

(7)

int(((-.4*sin(t)-.5333333334*sin(.6666666668*t))^2+(.4*cos(t)-.5333333334*cos(.6666666668*t))^2)^(1/2), t)

-1.120000000*((0.2133333334e20*cos(.8333333334*t)^2-0.2177777778e20)*(cos(.8333333334*t)^2-1.))^(1/2)*(-1.*cos(.8333333334*t)^2+1.)^(1/2)*EllipticE(cos(.8333333334*t), .9897433186)/((0.2133333334e20*cos(.8333333334*t)^4-0.4311111112e20*cos(.8333333334*t)^2+0.2177777778e20)^(1/2)*sin(.8333333334*t))

(8)

evalf(VectorCalculus:-`+`(limit(-1.120000000*((0.2133333334e20*cos(.8333333334*t)^2-0.2177777778e20)*(cos(.8333333334*t)^2-1.))^(1/2)*(-1.*cos(.8333333334*t)^2+1.)^(1/2)*EllipticE(cos(.8333333334*t), .9897433186)/((0.2133333334e20*cos(.8333333334*t)^4-0.4311111112e20*cos(.8333333334*t)^2+0.2177777778e20)^(1/2)*sin(.8333333334*t)), t = VectorCalculus:-`*`(6, Pi)), VectorCalculus:-`-`(limit(-1.120000000*((0.2133333334e20*cos(.8333333334*t)^2-0.2177777778e20)*(cos(.8333333334*t)^2-1.))^(1/2)*(-1.*cos(.8333333334*t)^2+1.)^(1/2)*EllipticE(cos(.8333333334*t), .9897433186)/((0.2133333334e20*cos(.8333333334*t)^4-0.4311111112e20*cos(.8333333334*t)^2+0.2177777778e20)^(1/2)*sin(.8333333334*t)), t = 0))))

Float(undefined)

(9)

simplify(diff(-1.120000000*((0.2133333334e20*cos(.8333333334*t)^2-0.2177777778e20)*(cos(.8333333334*t)^2-1.))^(1/2)*(-1.*cos(.8333333334*t)^2+1.)^(1/2)*EllipticE(cos(.8333333334*t), .9897433186)/((0.2133333334e20*cos(.8333333334*t)^4-0.4311111112e20*cos(.8333333334*t)^2+0.2177777778e20)^(1/2)*sin(.8333333334*t)), t))

.9333333334*(1.-.9795918367*cos(.8333333334*t)^2)^(1/2)

(10)

``

Download hypotrochoid.mw

I have many integrals which I would like to calculate the value. The one in attachment is the simpliest example.

It shows 'too many level of recursion',

I know that it has something to do with the piecewise, however, it shouldn't, right? Any insights?

evalfandintPerformance.mw

evalfandintPerformance.pdf

I've implemented the optimal taxation model proposed in this paper using Maple.

But it never stops running and get stuck in the last line for integral computation. Any idea of what's wrong with that?

This is the last line:

Here is the full code.

If I calculate the integral:

z:=exp(I*t)

evalf(Int(z^(1/2)*(diff(z, t)), t = 0 .. 2*Pi))

I get -1.33333333*I

If I calculate

int(z^(1/2)*(diff(z, t)), t = 0 .. 2*Pi)

I get -4/3

so where is the I coming from? Am I doing sth  something   wrong?

I might add: if I calculate the same for z:=0.5+exp(I*t) I get 0 and -I*0.4714....

so what is going different here?

I am trying to perform the following integral:

Which spits the integral back out at me.

I've also tried

Which, again, spits the integral back out at me.

My last attempt was this

Which... Still spit back out the integral.

Is there something special I should be doing for functions I'm integrating with a natural log? I need to get an exact value for this, not an approximation (because I am trying to check the accuracy of an approximation with this!).

Thanks!

Hi, I try Aproximate integral with simpsons method, but i want value in function the a with number solution:

 

with(Student[Calculus1]);
ApproximateInt(a*tan(x)-2*x, x = -100 .. 100, method = simpson, output = plot, partition = 500);

This error.

 

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

I am tryng to change variables in multiple integral as below, but receive error. Help me to do so.
 

``

restart

Error, invalid input: with expects its 1st argument, pname, to be of type {`module`, package}, but received shareman

 

with(IntegrationTools):

V := Int(Physics:-`*`(f(Physics:-`^`(x, 2)), g(y)), [x = a .. b, y = c .. d])

Int(f(x^2)*g(y), [x = a .. b, y = c .. d])

(1)

``

Change(V, {x = u-W, y = v-Q})

Error, (in IntegrationTools:-Change) missing a list with the new variables

 

``


 

Download inttt.mw

The maple I used at school is a much older version and when I do Definite Integrals there and copy it to Word as part of the project, it just copies perfectly.

Now I have Maple 16 at home and when I have a definite integral, I have to copy it using copy special and take it as an image to MS Word. That's not the problem. The problem is the limits sometimes seem to be cut off. The left hand-side image is the older version of Maple. Limits look perfect and even the integral sign is darker and so on. The right hand-side image is the Maple 2016. Can anyone help me change the style on Maple 2016 so it's like the old one so the integrals look better on my project. Thanks alot

 

I am trying to calculate the integral

where

Maple cannot calculate the integral. I tried to expand theta in the series form and substitute in the integral, still cannot calculate it.

any suggestion to tackle this problem whould be helpful.

Thank you

 

hi.

please help me for remover this problem.

''''

-Float(infinity)*signum((5.*A3*A1-24.*A2^2)*A1/A2^2)''''

ReducedCantiler.mw
 

restart

f := -(2/3)*eta^3+(1/2)*eta^2+eta; -1; g := -eta^2+1; -1; h := -eta^2+1; 1; F := proc (eta) options operator, arrow; A1*f end proc; 1; G := proc (eta) options operator, arrow; A2*g end proc; 1; H := proc (eta) options operator, arrow; A3*h end proc

proc (eta) options operator, arrow; A3*h end proc

(1)

Q1 := diff(F(eta), eta, eta, eta)+.5*H(eta)*((diff(F(eta), eta))^2+F(eta)*(diff(F(eta), eta, eta)))/G(eta)^2+2*(diff(G(eta), eta))*(diff(F(eta), eta, eta))/G(eta)-(diff(H(eta), eta))*(diff(F(eta), eta, eta))/H(eta); 1; Q2 := diff(G(eta), eta, eta)+H(eta)*((diff(F(eta), eta))*G(eta)+.5*F(eta)*(diff(eta, eta)))/G(eta)^2+2*(diff(G(eta), eta))^2/G(eta)-((diff(H(eta), eta))*(diff(H(eta), eta)))/H(eta)+(diff(F(eta), eta, eta))^2-(H(eta)/G(eta))^2; 1; Q3 := diff(H(eta), eta, eta)+(.5*1.3)*H(eta)*(5*(diff(F(eta), eta))*H(eta)+F(eta)*(diff(H(eta), eta)))/G(eta)^2+2*(diff(G(eta), eta))*(diff(H(eta), eta))/G(eta)-(diff(H(eta), eta))^2/H(eta)+(1.3*1.44)*H(eta)*(diff(F(eta), eta, eta))/G(eta)-(1.3*1.92)*(H(eta)/G(eta))^3

-2*A3+.65*A3*(5*A1*(-2*eta^2+eta+1)*A3*(-eta^2+1)-2*A1*(-(2/3)*eta^3+(1/2)*eta^2+eta)*A3*eta)/((-eta^2+1)*A2^2)+4*A3*eta^2/(-eta^2+1)+1.872*A3*A1*(-4*eta+1)/A2-2.496*A3^3/A2^3

(2)

Eq1 := int(Q1*f, eta = 0 .. 1);

-0.2600000000e-1*A3*(24.*A1*A2^2-65.*A1*A2*A3+64.*A3^2)/A2^3

(3)

sol := solve({Eq1 = 0, Eq2 = 0, Eq3 = 0}, {A1, A2, A3}); J := min(select(`>`, sol, 0))

Error, invalid input: `>` expects 2 arguments, but received 1

 

A11 := evalf(simplify(sol[1, 1])); A22 := evalf(simplify(sol[1, 2])); A33 := evalf(simplify(sol[1, 3]))

Error, invalid subscript selector

 

``


 

Download ReducedCantiler.mw

 

Hi,

I have a second order, linear, non-homogeneous differential equation and for the solution Maple takes the particular solution under a indefinite integral form. After I substitute the values of the coefficients I want Maple to perform the integration. The integration is possible because I individually integrated one small part of the expression. The full expression has a lenghty sumation of different indefinite integrals so it would be cumbersome to perform each integration by hand.

Can somebody help me force Maple to perform these integrations?

I already tried eval, evalf, simplfy and it doesn't work.

Thanks a lot.

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