Hello,

      I would like to solve a system of 9 nonlinear equations, with the constraints on all 9 variables to be that they are nonnegative. How can I do this?

My code is below - I am trying NLPSolve and have tried solve, but am getting stuck.

with(Optimization);

restart; eq1 := 531062-S/(70*365)-(.187*(1/365))*(H+C+C1+C2)*S/N = 0;eq2 := (4/365*(T+C))*S/N-(.187*(1/365))*(H+C+C1+C2)*T/N-(1/(70*365)+1/(5*365))*T = 0; eq3 := (.187*(1/365))*(H+C+C1+C2)*S/N-(4/365)(T+C)*H/N-(1/(70*365)+1/(4*365))*H = 0; eq4 := (.187*(1/365))*(H+C+C1+C2)*T/N+(4/365*(T+C))*H/N-(1/(70*365)+3/(8*365)+.2*(1/365)+.1)*C = 0; eq5 := .1*C-(1/(70*365)+1/(4*365)+1/60+.5)*C1 = 0; eq6 := (1/60)*C1-(1/(70*365)+1/(4*365)+1/210+.5)*C2 = 0; eq7 := .5*C1-(1/(70*365)+1/60+0.1e-2)*CT1 = 0; eq8 := .5*C2-(1/(70*365)+1/210+(1/9)*(0.1e-2*7))*CT2+(1/60)*CT1 = 0; eq9 := N-S-T-H-C-C1-C2-CT1-CT2 = 0; soln := NLPSolve({eq1, eq2, eq3, eq4, eq5, eq6, eq7, eq8, eq9}, {C, C1, C2, CT1, CT2, H, N, S, T}, assume = nonnegative);

The problem is The square root of 16-x^2 over the interval [0,-4]  0 being the upper bound, -4 being the lower bound.  I have solved 3/4s of this problem but I don't understand what they mean by "Solve the definite integral exactly by geometry". 

I'm trying to substitute one Differential equation into another differential equation.

eq1:=d*n(t)/dt = (rho(t)-beta)*n(t)/Lambda+lambda*C(t)+q

eq2:=diff(eq1, t)

resulting in -> eq2 := d*(diff(n(t), t))/dt = (diff(rho(t), t))*n(t)/Lambda+(rho(t)-beta)*(diff(n(t), t))/Lambda+lambda*(diff(C(t), t))

then I'm given that (diff(C(t), t)) is given by another equation: 

eq3:=d*C(t)/dt = beta*n(t)/Lambda-lambda*C(t)

At this point I'm trying to substitute equation 3 into equation 2 for diff(C(t),t)

eq4 := subs(diff(C(t), t) = rhs(eq2), eq5)

however no matter what way's I try this I get an error: 

Error, (in simpl/reloprod) invalid terms in product: (d*(diff(n(t), t))/dt = (diff(rho(t), t))*n(t)/Lambda+(rho(t)-beta)*(diff(n(t), t))/Lambda+lambda*(diff(C(t), t)))^-1

I then tried to map it but again i got an error specifically about the first parameter: 

Error, invalid operator parameter name

eq5:=map((d/dt C(t))->beta/Lambda*n(t)-lambda*C(t),eq2)

I'm just wondering if what I am trying to do is even possible in Maple? 

If anyone can help I would greatly appreciate it! 

I am trying to recreate journal work for validating using another computer program so I am trying to use maple to solve the ODE, based on further research I found using laplace might be the best but I am having some trouble.

eq8:=d*(n(t)+C(t))/drho = -rho(t)/(l*alpha*K_c)

given the initial conditions of:

ICs:= n(0) = n_0, rho(0) = rho_0, C(0) = (beta-rho_0)*n_0/(l*lambda)

therefore: 

equation9 := dsolve({equation8, ICs}, {C(t), n(t)}, method = laplace)

Following this process I get the error: 

Error, (in dsolve) invalid initial condition

According to the journal work the solution I am looking for is: 

C(t)=-n(t)+(rho_0^2+rho(t)^2)/(2*l*alpha*K_c)+((Beta+l*lambda-rho_0)*n_0)/(l*lambda)

is there something that I'm doing wrong or missing? 

Any help would be greatly Appreciated! 

I am trying to define some functions by recursion relations but I get this error:

Error, (in type/realcons) too many levels of recursion

Please see the attached file for details:

File.mw

In this document, I think that is the relevent section. But I couldnt understand it.

I want something like this

>plot(sin(x),color=yellow);

>plot(sin(x),color=organe);

>plot(sin(x),color=red);

>plot(sin(x),color=green);

>plot(sin(x),color=ABC); # error

>plot(sin(x),color=CBA);# error

optional, but works fine within a given sets of choices.

How do I write a procedure like that?

Thanks!

we have number from 1 to 2014. If we underline the number that divide by 3 and 4, how many pattern of two underlines that next to each other as example?(1,2,3,4,5,6,7,8,9,10,...,2014).

I have a nonlinear system with 4 equations and 4 unknowns. I am using fsolve. I know that there are multiple solutions for each variable but am only getting one. I need the others. what do I do??

This is my code:

R__1 := Matrix([[1, 0] , [0, 1] ]);

R__2 := Matrix([[1/2, sqrt(3)/2] , [-sqrt(3)/2, 1/2] ]);

R__3 := Matrix([[-1/2, sqrt(3)/2] , [-sqrt(3)/2, -1/2] ]);

R__4 := Matrix([[-1, 0] , [0, -1] ]);

R__5 := Matrix([[-1/2, -sqrt(3)/2] , [sqrt(3)/2, -1/2] ]);

d__1 := Vector( [ 0, 5.4] );

d__2 := Vector( [ 6.4, 4.539] );

d__3 := Vector( [ 11, 4.078] );

d__4 := Vector( [ 15.5, 2.079] );

d__5 := Vector( [ 19, 1.039] );

a := Vector( [ a__x, a__y] );

A__1:=R__1.a+d__1;

A__2:=R__2.a+d__2;

A__3:=R__3.a+d__3;

A__4:=R__4.a+d__4;

A__5:=R__5.a+d__5;

OO:=Vector([O__x,O__y]);

DA1:=A__2.A__2-A__1.A__1-2*(A__2-A__1).OO;

DA2:=A__3.A__3-A__1.A__1-2*(A__3-A__1).OO;

DA3:=A__4.A__4-A__1.A__1-2*(A__4-A__1).OO;

DA4:=A__5.A__5-A__1.A__1-2*(A__5-A__1).OO;

fsolve({DA1,DA2,DA3,DA4},{a__x,a__y,O__x,O__y});

Thanks for any tips you may be able to offer

How do I plot the following equations in Maple ?:

I already tried this: 

According to the given solution the plot should look like that: 

I think I have to tell maple that the function is defined from R^2 -> R, but I don't know how to do this. 

Thanks in advance for your kind help.

I want to get the result of multi-matrix multiply like followed below,

but error "final value in for loop must be numeric or character"

(*n is arbitrary and B[1],B[2],...,B[n] have been obtained*)

A:=LinearAlgebra:-IdentityMatrix(n);
#using the multiplication operation of matrix
for i from 1 to n do
   A:=LinearAlgebra:-Multiply(A,B[i]);
od:

return A

help me 

thanks

Hello, Im trying to do a jocobian

http://www.maplesoft.com/support/help/Maple/view.aspx?path=VectorCalculus/Jacobian

but when I try the example code

jacobian([rcos(t), rsin(t), r^2*t], [r, t])

i only get the output as 

jacobian([rcos(t), rsin(t), RandomMatrix(4, 4*density = .75, outputoptions = [shape = tringular*lowe])^2*t], [RandomMatrix(4, 4*density = .75, outputoptions = [shape = tringular*lowe]), t])

I want the output as a matrix as in the example url.

Thanks

hello . i have a Partial differential equation i need some help with 

This is how it goes 

As stated, contourplot3d is not displaying contours. Even in the Maple Help examples the contours are not displayed in the help screen.

In this example:

contourplot3d(-5*x/(x^2+y^2+1), x = -3 .. 3, y = -3 .. 3, filledregions = true);

which is directly from Maple Help, the surface is plotted (with boxed axes), but no contours appear.

When I try

contourplot3d(-5*x/(x^2+y^2+1), x = -3 .. 3, y = -3 .. 3);

the plot shows nothing except boxed axes.

I've also tried

plot3d(-5*x/(x^2+y^2+1), x = -3 .. 3, y = -3 .. 3, contours=6);

and the surface shows but without countours. Furthermore, the Maple scripts that worked previously in earlier versions (showing contours via plot3d) now do not show contours in Maple 18. This occurs on both Win 7 and Win 8 laptops.

Thanks!

Hello everybody

I am working on the bending of FGM plate, and I just used maple for the calculation functions of my problem of the bending of FGM plates.

Can any from the members of mapleprimes one help me to write Navier's equation include below for the bending of the plate because I am new in using Maple 18

alfa=m*pi/a, beta=n*pi/b with m=1,3,5..100 and n=1,3,5...100

Thank's for all 

Presentations of the first national congress of civil engineering developed at the University Cesar Vallejo. From 10 to 12 November 2014.

CONIC_UCV.pdf

(in spanish)

Lenin Araujo Castillo

Physics Pure

Computer Science