## Solving system of equations...

Hello everybody

In the attached file, I tried to solve the system of equations and obtain the parametric solution for my unknowns that are A1, A2, A3, A4, A5, A6, A7 and A8. I have 8 equations and 8 unknowns. The other variables are all known and parametric. I thought Maple could solve these system of equations easily but when I ran the program and waited for about 2 hours, unfortunately it returned no answer and it was in evaluating mode and I closed the program forcely. Does my file have any problem or Maple cannot solve these system of equations.

SOE.mw

## dsolve with unknown prameter omega...

hi .how i can solve nonlinear equation with unknown prameter omega as below

thanksfrekans.mw

## Finding unknowns from a set of equations...

Hello everybody.

In the attached file, you find 6 equations. All of these parameters are known except "pd" and "qd". How can I find these two unknowns from 6 equations??? It should be pointed out that, "pd" and "qd" must contain "ud", "vd","wd" and "rd".

D.mw

## dsolve with unknown parameter...

hi.I want to dsolve set of nonlinear equations with one unknown parameter ...is this possible with dsolve rule.in matlab this possible with bvp4c rule..please help me for this problem.if we should another rule please attached file reform.Thanks alot12.mw

## How to determine unknown value in boundary conditi...

Hello everyone,

How can unknown values in boundary conditions of system ODEs be determine by using shooting technique. See the work sheet here Sht.mw

Thanks.

## solve system symbolic...

Hello every one,

I had a 3 equations with 3 unknown (X,Y,Z, conjugate(Y),conjugate(Z))

this is the code:

solve( {ao*x + a1*y + conjugate(a1)*conjugate(y)+a2*z+conjugate(a2)*conjugate(z) = 0.5, conjugate(a1)*x + bo*y + conjugate(a2)*conjugate(y)+a1*z = 0, 10*x + 10*y/4 + 10*z = 10}, {x, y, z});

where the coefficients are complex numbers

Is thee any simple way to solve it

thanks

## Error, (in rtable/Power) singular matrix...

Hi,

I have an error how can I fix the error. Thank you.

Matrix_Fred:=proc(N,d,lambda)
local Kernel,K,Fredholm,phi,MatA,eq2,eq3,eq4,Vct_basis,fct,sys,M,b,M1,Vect_beta,W,i,beta,alpha,eq5,eq6,x,Subs1,Fredholm_stencil,Stencil,w,V,sys1,sys2,Subs2,sys3,Sol_phi;
Fredholm:=phi(x)=f(x)+lambda*int(Kernel(x,y)*phi(y),y=-a..a);
Kernel:=(x,y)->ln(abs(x-y));
eq2:=int(Kernel(x,y)*phi(y),y=-a..a)=sum(int(Kernel(x,y)*phi(y),y=n*h..(n+d)*h),n=-N..N-d);
Vct_basis:=[seq(x^i,i=0..d+1)];
fct:=[seq(unapply('Vct_basis[i]','x'),i=1..d+2)];
sys:=[seq(eq3(fct[i]),i=1..d+1)];
w := [seq(beta[i,n],i=1..d+1)];
M,b := GenerateMatrix(sys,w);
M1:=-M; V:=-b;
Vect_beta:=(M1)^(-1).V;
for i from 1 to d+1 do
beta[i,n]:=Vect_beta[i];
end do;
x:=m*h;
for i from 1 to d+1 do
alpha[m,n,i]:=unapply(beta[i,n],n,m);
end do;
eq5:=lhs(eq2)=sum(rhs(eq4), n=-N..N-d);
eq6:=subs(x=m*h,subs(lhs(eq5)=rhs(eq5) ,Fredholm)):
Subs1 :=[seq(phi(m*h)=phi[m], m=-N..N)];
Fredholm_stencil:=subs(Subs1,eq6):
Stencil[1] := unapply(Fredholm_stencil,m,lambda,phi,f);
sys1 := [seq(Stencil[1](m,lambda,phi,f),m=-N..N)]:
sys2:=subs(Subs1,sys1):
Subs2:=[seq(f(m*h)=f[m], m=-N..N)]:
sys3:=subs(Subs2,sys2):
Sol_phi := [seq(phi[i],i=-N..N)]; # The unknown vector must be computed.
MatA := GenerateMatrix(convert(sys3,list),Sol_phi)[1];
return MatA;
end proc:

d:=1; N:=2; lambda:=3/Pi;
Matrix_Fred(N,d,lambda);
1
2
3
--
Pi
Error, (in rtable/Power) singular matrix

## defining the periodicity of an unknown function...

Hi,

Suppose you have an unknown function y(x)  that is 2*Pi periodic, i.e. (y(0) = y(2*Pi)). Is there a way to declare this in Maple? The reason I want to do this, is that if I integrate the derivative y'(x) of  this unknown function on [0,2*Pi]I would like Maple maple to be able to recognize that:

int(y'(x),x=0..2*Pi) =0

Thanks

## problem with function solve...

Hi,

I am trying to solve the following system using the function "solve", but the message "warning solutions may have been lost" appears.

This is my script (a,b,c,d,e,f, Resp, Malcyt,Pyrcyt are parameters). The unknown variables are Citcyt, Citmt,Malmt,Pyrmt:

`e1 := 0 = a.Pyrcyt-a.Pyrmt+(b-c).Malmt; e2 := 0 = d.Malcyt+e.Citmt-(d+b+c).Malmt; e3 := 0 = f.Citcyt+c.Malmt-(e+f).Citmt;`
` e4 := 0 = 2.*e.Citmt+(b+c).Malmt-Resp;`

## Has Maple failed to solve my system of equations?...

Hey Guys,

I'm trying to solve a system of 5 linear equations to get 5 unknowns:

## How do I find the unknown X when I know Y?...

well first of all this site was very useful for doing my homework, but there is still something I didnt find on it and im sure other people may find it useful.

I have a system of 5 ode's and 6 initial conditions that ive solved successfully and plotted the graphs i need:  Position VS Time

Speed VS Time

The only thing I initially know is the final position, which i can read on the first graph and...

## Error, invalid input...

Good Morning.

I have a problem

i have two functions

`> xcir(t):=0.3 + 0.15*sin(t):> ycir(t):= -0.3-0.15*cos(t):`
` `
`and i suppose that i have a problem in the following equation`
`> qd2 := ((arctan(-ycir(t)/xcir(t))-arctan(.45*sin(qd3(t))/(.45+.45*cos(qd3(t)))))*180)/(3.1416);> qd3 := 180*arccos((xcir(t)*xcir(t)+ycir(t)*ycir(t)-.45*(2*.45))/(.45*(2*.45)))/(3.1416);`
` `

## Error, in Odeplot curve is not fully specified in ...

Good Morning.

I have problem when i want to graph my equations. I received this error:

`Error, (in plots/odeplot) curve is not fully specified in terms of the ODE solution, found additional unknowns {t}`
`I would like to know how i can solve it`
`Thanks in advance  `
 ...

## Two equations in two unknows...

I have just tried to solve for 2 equations in 2 unknowns. The 2 equations are very non-linear. I know for a fact that there are 2 solutions as I can draw the curve, but for some reason and for some parameter specifications Maple will only give me 1 out of the 2 solutions. I use the following:

Solve( [eq1,eq2] , [x,y])

Christian

## MAPLE wont evaluate a matrix with an unknown...

Hi,

I need to find the eigenvectors of this matrix and get the following error:

> eigenvects(A);
linalg:-eigenvects called with arguments: [[200, -96, 5, -4.4, 4.7, -12.6, -6.2], [-96, 320, 33.1, 6.8, 4.5, 7.4, -.3], [5, 33.1, z, -51.1, .8, -8.4, 7.6], [-4.4, 6.8, -51.1, 110, -76.6, -14.2, -67], [4.7, 4.5, .8, -76.6, 270, 78.3, -.1], [-12.6, 7.4, -8.4, -14.2, 78.3, 420, 38.3], [-6.2, -.3, 7.6, -67, -.1, 38.3, 230]]
#(linalg:-eigenvects,7...

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