I need help for two exercise. In the first I have in the secondary circuit nothing, in the second exercise un inductor.thanksinduzione_fra_due_circuiti.msim

Hi :-(

Just type this little set of lines (presently in Maple 2018, not checked for older versions)

restart:
with(Statistics):
N := ... Some integer value >= 2;  
X := RandomVariable(Binomial(N, 1/2)); 
plot(CDF(X, s), s=-1..N+1, gridlines=true, axis[1]=[gridlines=N+1]);

You will be horified by the results you obtain:
Whatever the value of n in [2, 5] the CDF is null for s < 0 (good), equal to 1 for s > N (good also) ... and equal to 1 in between

I didn't check with p = 0.5 instead of 1/2, neither for other values.
Surprinsingly the PDF is correct for any integer n



 

I want to solve system of nonlinear ordinary differential equations numerically using the variational finite
element method (FEM). is it possible to solve on Maple? If anybody have a idea please share with me. I attach the image of my problem which I am tryimng to solve.

There was a streamlines question that has dissappeared.  Where did it go?  Why was it deleted?

Below is a picture of my code and the errors that have arisen when I have tried to use a 2-level indice within a loop and dsolve. I will also paste in the code below.

restart;

with(PDEtools); umain := 1-exp(-y)+sum(A^i*u[i](y, z), i = 1 .. 4); vmain := -1+sum(A^i*v[i](y, z), i = 1 .. 4); wmain := sum(A^i*w[i](y, z), i = 1 .. 4); pde[main] := diff(vmain, y)+diff(wmain, z); pde[main[2]] := vmain*(diff(wmain, y))+wmain*(diff(wmain, z))-(diff(wmain, y$2));

for i to 1 do pde[i] := coeff(pde[main[2]], A^i) = 0; w[i](y, z) := sum(sol[i, k](y)*sin(k*z), k = 1 .. i); for j to i do sys__i__j := [-(diff(sol__i__j(y), y))-(diff(sol__i__j(y), y$2)) = coeff(pde[main[2]], sin(j*z)), sol__i__j(0) = 0, sol__i__j(infinity) = 0]*dsolve([-(diff(sol__i__j(y), y))-(diff(sol__i__j(y), y$2)) = coeff(pde[main[2]], sin(j*z)), sol__i__j(0) = 0, sol__i__j(infinity) = 0]); assign(op(0, sol__i__j*y)) = unapply(dsolve(sys__i__j), op(dsolve(sys__i__j))) end do end do

I have learned that the eigenvectors of an solid object's Inertial Tensor are its principal axes and are an orthonormal set, however two of the eigenvectors in the cube in the uploaded worksheet are not orthogonal.

Where is my error?

CubePrincipalAxes.mw

Hi,

Let a in ] 0, 1[  and  x real

Let  f := sin(x) / ( ( sin(a*x) )^a * ( sin((1-a)*x) )^(1-a) );

How can I find the limit of f as x goes to 0 ?
(limit, series, taylor don't work, wether I set or not assumptions on "a" [assume/assuming])

PS 1:  the limit is found once a numeric value is given to alpha

PS 2:  By simple calculations:
           sin(x) ~x  ;  sin(a*x) ~ ax  ; sin((1-a)*x) ~(1-a)x and thus
          ==>  f(x->0) ~ x / ( -a*x)^a * ((1-a)*x)^(1-a) )
                              = x / ( -a^a * (1-a)^(1-a) * x^(a+1-a)
                              = 1 /  ( -a^a * (1-a)^(1-a)  )

I am trying to solve system of coupled equations in maple, but when I execute it, maple gives a trivial answer. Here is the code:

de1:=diff(u1(x,t),x)=(i/lambda)*(p*u1(x,t)+q*u2(x,t));
                  d             i (p u1(x, t) + q u2(x, t))
           de1 := -- u1(x, t) = ---------------------------
                  dx                      lambda

> de2:=diff(u2(x,t),x)=(i/lambda)*(q*u1(x,t)-p*u2(x,t));

                  d             i (q u1(x, t) - p u2(x, t))
           de2 := -- u2(x, t) = ---------------------------
                  dx                      lambda

> de3 := diff(u1(x,t),t) = -(i*lambda/2)*u1(x,t)-q*u2(x,t);

             d
      de3 := -- u1(x, t) = - 1/2 i lambda u1(x, t) - q u2(x, t)
             dt

> de4 := diff(u2(x,t),t) = 1/2*i*lambda*u2(x,t)+q*u1(x,t);

              d
       de4 := -- u2(x, t) = 1/2 i lambda u2(x, t) + q u1(x, t)
              dt

> dsolve({de1,de2,de3,de4},{u1(x,t),u2(x,t)});
 

I have an equation

2*x + 3*x^3

would like to change to

x1 + x2 + x3*x4*x5 + x6*x7*x8 + x9*x10*x11

hey 

mathcad contains a command explicit all wich shows the equation with all the named variabels replaced with the numbers they repercent. can maple do something similar?

a:=5

B:=10

c:=a+b explicit all 5+10=15

i hope someone can point me in the right direction 

thanks 

I have defined a function, F, as

F:=(s)->fouriersin(f(r), r, s)

I would now like to plot that function.

plot(F(s), s=0..3)

How can I do that? Calls to plot don't work, as the "s" in the fouriersin definition of the function get replaced by the value I'm trying to plot.

Hi,

Is there any one can tell me why I get so many solutions there by use solve(f(x),{x,y},explicit)? There suppose to be only two solutions. Thanks in advance!

Hello,

Can anyone tell me why this Maple phaseportrait command returns the error below ? Thanks in advance !

with(DEtools);
phaseportrait(-2*x*y, [x, y], x = -1.5 .. 1.5, {[0, -2], [0, -1], [0, 0], [0, 1], [0, 2], [0, 3]}, y = -1 .. 3);
Error, (in DEtools/phaseportrait) system must have same number of dependent variables as DE's.
 

Hello

The calculation of the jacobian matrix is not working.

https://de.maplesoft.com/support/help/maple/view.aspx?path=VectorCalculus/Jacobian

Testes on windows, mac. worhksheet and document mode.

Maple 2017.

Download DAROTIERTJACOBIANIMGRABSCHEISSEMA.mw

There seems to be patterns for sin(10^-k) for rational k;

Here we have the "floats."

n sin(10^(-n-1/2))

1 0.03161750640

2 0.003162272390

3 0.0003162277607

4 0.00003162277660