Sometimes my code works and sometimes I have this kind of error: 

I am using one argument for cosine and the following operations:

Thanks !

Hello,i cant solve this expression in maple,What is the integral result?

Thanks.

Hello

I am having issue in finding the explanation on how to solve inverse trig funtion and expression with inverse trig funtions. I do not understand my school book and I was hoping that the software would have given me an extra help in understanding my school problems. 

Thank you very much

Regards,

Perla D'andrea

Hello everyone,

I have a problem with my  code, breif this is the equation that I want to solve 

x^2*(diff(y(x), x, x))+50*x*(diff(y(x), x))-35*y(x) = (1-exp(x+1))/(x+1)+(x^2+50*x-35)*exp(x)+int(exp(xt)*y(t), t = 0 .. 1), x = 0 .. 1

but the problem is that I don't know how to code the integral please guys help me 

Hello people in mapleprime,

Though I wrote the title as Fundamental theorem of calculus,

what I am considering is just how to continue the chain of codes in calculation.

restart;

#I defined F__0 as

F__0:=x->Int(f(t),t=a..x);

#Then, the difference between a primitive function of f(x), F(x), and F__0 is no more than a constant C, so I write.

bb:=F(x)-F__0(x)=C;

#Then, substituting "a" into equation "bb", I obtain the value of F(a)

bb1:=subs(x=a,bb):cc:=simplify(%);

#Then, I substituted the value of C in "bb1" into "bb,"  obtaining the following "cc1."

cc1:=subs(isolate(cc,C),bb);

#And, then, I isolated the term of Int(f(t),t=a..x)  in cc1,

dd:=isolate(cc1,Int(f(t), t = a .. x));

#And, then, I substitute x=b into the outcome of dd, and obtain the final equation.

subs(x=b,dd);

Surely, with the above code, I could get the fundamental theorem. But, it looks in a little roundabout way.

So, I thought I would ask here about whether there aren't any better ways to do the fundamentally the same thing or

hints to improve the above code.

Please teach me about this.

Thanks in advance.

taro

Hi

I need to solve below integro-differential equation

0.3846153846*(diff(F(x, y), y, y))+diff(F(x, y), x)-(diff(w(x), x, x))*y-(1/2)*(int(diff(F(x, y), x), y = -1 .. 1))+diff(F(x, y), x, x)-(diff(w(x), x, x, x))*y-(1/2)*(int(diff(F(x, y), x, x), y = -1 .. 1))

The solution is as follows:

(diff(w(x), x))*y-_C1*y/exp(x)-(1923076923/5000000000)*_c[2]*x*y+_C2*y+(1/6)*_c[2]*y^3+_C4*y+_F1(x)

The parameters _C1, _C2, c[2], C4 are functions of x, or functions of y? Or these parameters are constant numbers? 

In addition to, is it reasonable to use C *y instead of _C2*y+_C4*y ?

Thank you

n := 5:
z1 := exp(2*3.14*I*k1/n)*cosh(z)^(2/n);
z2 := exp(2*3.14*I*k2/n)*sinh(z)^(2/n);
xx := Re(z1);
yy := Re(z2);
uu := cos(alpha)*Im(z1) + sin(alpha)*Im(z2);

use above example of calabi yau equation, do not know which variables z, k1, k2 are u and v, then i assume k1 and k2 are u and v respectively,

E := diff(xx,k1).diff(xx,k1);
F := diff(xx,k1).diff(xx,k2);
G := diff(xx,k2).diff(xx,k2);

then calculate metric
diff(E, k2);
F
diff(G, k1);

which function can input these metric diff(E,k2), F, diff(G,k1) to prove calabi yau equation's metric's ricci is flat

Round := proc(x,n::integer:=1)
parse(sprintf(cat("%.",n,"f"),x));
end proc:

roundcoeffs1:=proc(p,x,n:=1) local t,c;
c:=map(Round, [coeffs(p,x,t)],n);
add(i, i = zip(`*`, c, [t]));
end:

ggg:=.9940413618*y^3-1.785839107*c*A*y^3-2.357517322*c*A*y^2+.375393240*c*y*B-.3575173222*c*A*y-.2082022533*c*B-0.1787591445e-1*y^2-0.1787591445e-1*y-0.5958638151e-2+.2141608926*c*A+.7917977467*c*B*y^3+2.375393240*c*B*y^2;

roundcoeffs1(ggg, [y^3, c*A*y^3, c*A*y^2, c*y*B, c*A*y, c*B, y^2, y, c*A, c*B*y^3, c*B*y^2], 4);

Error, (in sprintf) number expected for floating point format

hi.please help me for gain result with out root of form....

thanks

root_of.mw

Download root_of.mw

hi .i have a problem with dsolve this equation.please help me for removing error

"initial Newton iteration is not converging"

thanks..

SGT-FDM.mw

Download SGT-FDM.mw

Hi, Maple community

I am trying to integrate a 3D data numerical set. I managed to execute an array interpolation algorithm and apply it to plot a smooth surface but I do not know how to integrate it numerically. I want to be able to integrate the data not only in its domain but also in sub-domains for multiple purposes.

I've found here a topic about it and tried to apply suggestions made with no success.

Here I copy the worksheet steps:

restart:
with(LinearAlgebra):
with(CurveFitting):
with(plots):

Initial Parameters

Nx:=8;    Points in the x direction
Nz:=6;    Points in the z direction
Lx:=3;    This means x goes from 0 to 3
Lz:=2;    This means z goes from 0 to 2
Delta[ze]:=evalf(Lz/(Nz-1));
Delta[xe]:=evalf(Lx/(Nx-1));

DataPn:=Matrix(Nx,Nz,0):         Matrix to store values in the 3rd direction

The following step is a function that I used to simulate data that I will later on will get by measurings.

for i from 1 to Nx do
 for j from 1 to Nz do
  DataPn[i,j]:=evalf(sin(Pi*(i-1)*Delta[xe]/Lx)*sin(Pi*(j-1)*Delta[ze]/Lz)):
 end do;
end do;

Setting data to use ArrayInterpolation

datax:=Array([seq((i-1)*Delta[xe],i=1..Nx)]);
dataz:=Array([seq((j-1)*Delta[ze],j=1..Nz)]);

In this step here, I don't really understand what this argument [[a],[b]] means but ArrayInterpolation cannot work without it.

MI:=(a,b)->ArrayInterpolation([datax, dataz],Array(DataPn),[[a],[b]],'method' = 'spline')[1,1];

Plot and display the interpolation and the real function to compare the quality of the interpolation, actually it does an excellent job, at least with this data.

G1:=plot3d(MI, datax[1]..datax[Nx], dataz[1]..dataz[Nz],labels=[x,z,Pn]);
G2:=plot3d(evalf(sin(Pi*x/Lx)*sin(Pi*z/Lz)),x=0..3,z=0..2,color=red);
display(G1,G2);

And finally I found this integration method here in mapleprimes

evalf(Int(x->evalf(Int( y->MI(x,y), 0..3,method=_d01akc)),0..2,method=_d01akc));

And the result is 1.102279199. I thought maybe I was setting wrongly the integration limits or the order in the command but in any case the result was near the analytic case which was:

int(evalf(sin(Pi*x/Lx)*sin(Pi*z/Lz)),x=0..3,z=0..2);

2.431708408

In this scenario I know the result is wrong because I can compute the exact solution, but later on I won't be able to do so. Also, later I'm interested in the integration, let's say, x from 0..0.5 and later from 0.5..1 and so on (keeping z always from 0 to 2) So, the main questions are:

1. Am I setting something wrong?
2. If I delete the method option in the integral, it takes a lot of time for the program to compute any result. Why?
3. Is there any other way to integrate this? I mean, any other way to write the command to compute the integral.
4. What does the [[a],[b]] argument stands for in ArrayInterpolation?

Regards and thanks for your help.

Hello,how can i find y0 in this equatin?

Dear all

I have a simple question about geometric series

What's the difference between g(2) and gg(2)

 Many thanks

Geometric_series.mw

hi.how i can draw a graph (s(x))(1) versus sigma?

thanksomega=30.mw

Download omega=30.mw

On maplesim how plot the transfer funtion vs frequency for the public domain example tuned mass dumper?