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Can anyone tell me how to use dsolve to find the solution to the problem in the attachment.  It is faily easy to do using substitution for homogeneous coefficients, but dsolve seems to put out a very complicated solution to the problem.

with(DEtools):

2*x*y(x)+(x^2+y(x)^2)*(diff(y(x), x))

2*x*y(x)+(x^2+y(x)^2)*(diff(y(x), x))

(1)

dsolve(%)

y(x) = ((1/2)*(4+4*(4*x^6*_C1^3+1)^(1/2))^(1/3)-2*x^2*_C1/(4+4*(4*x^6*_C1^3+1)^(1/2))^(1/3))/_C1^(1/2), y(x) = (-(1/4)*(4+4*(4*x^6*_C1^3+1)^(1/2))^(1/3)+x^2*_C1/(4+4*(4*x^6*_C1^3+1)^(1/2))^(1/3)-((1/2)*I)*3^(1/2)*((1/2)*(4+4*(4*x^6*_C1^3+1)^(1/2))^(1/3)+2*x^2*_C1/(4+4*(4*x^6*_C1^3+1)^(1/2))^(1/3)))/_C1^(1/2), y(x) = (-(1/4)*(4+4*(4*x^6*_C1^3+1)^(1/2))^(1/3)+x^2*_C1/(4+4*(4*x^6*_C1^3+1)^(1/2))^(1/3)+((1/2)*I)*3^(1/2)*((1/2)*(4+4*(4*x^6*_C1^3+1)^(1/2))^(1/3)+2*x^2*_C1/(4+4*(4*x^6*_C1^3+1)^(1/2))^(1/3)))/_C1^(1/2)

(2)

NULL

 

Download DEprob.mw

THE FOLLOWING CODE 

restart;

A:=Matrix([[ a , b ], [ c , d ]]);

a:=1; b:=0; c:=0; d:=1;

A; 

produces differents results under MAPLE 16  linux i386 and under MAPLE 16  linux amd64

in the first case the last evalution has the following printed output:

Matrix([[a,b],[c,d]])

on the second machine the printed output is

Matrix([[1,0],[0,1]])

Does anybody has an explication; I thought that the "coorect behaviour was the first one since tables use last-name evalutation. But now I am puzzled.

 

Following my previous question

http://www.mapleprimes.com/questions/200627-Lssolve-Midpoint

I wrote the following code

 

restart:
Phiavg:=0.06;
lambda:=0.05;
Ha:=0;
NBT:=0.5;
Nr:=500;
#N[bt]:=cc*NBT+(1-cc)*4; ## cc between 0 and 1
N[bt]:=cc*NBT+(1-cc^2)*0.75;


                              0.06
                              0.05
                               0
                              0.5
                              500
                                           2
                    0.5 cc + 0.75 - 0.75 cc
eq1:=diff(u(eta),eta,eta)+1/(mu(eta)/mu1[w])*(sigma-Nr*(phi(eta)-phi1[w])-(1-phi(eta))*T(eta)-Ha^2*u(eta))+((1/mu(eta)*(mu_phi*diff(phi(eta),eta)))*diff(u(eta),eta));
eq2:=diff(T(eta),eta)-1/(k(eta)/k1[w]);
eq3:=diff(phi(eta),eta)-phi(eta)/(N[bt]*(1-gama1*T(eta))^2)*diff(T(eta),eta);
 /  d   /  d         \\      1                                 
 |----- |----- u(eta)|| + ------- (mu1[w] (sigma - 500 phi(eta)
 \ deta \ deta       //   mu(eta)                              

    + 500 phi1[w] - (1 - phi(eta)) T(eta)))

             /  d           \ /  d         \
      mu_phi |----- phi(eta)| |----- u(eta)|
             \ deta         / \ deta       /
    + --------------------------------------
                     mu(eta)                
                    /  d         \   k1[w]
                    |----- T(eta)| - ------
                    \ deta       /   k(eta)
                                       /  d         \            
                              phi(eta) |----- T(eta)|            
/  d           \                       \ deta       /            
|----- phi(eta)| - ----------------------------------------------
\ deta         /   /                       2\                   2
                   \0.5 cc + 0.75 - 0.75 cc / (1 - gama1 T(eta))
mu:=unapply(mu1[bf]*(1+a[mu1]*phi(eta)+b[mu1]*phi(eta)^2),eta):
k:=unapply(k1[bf]*(1+a[k1]*phi(eta)+b[k1]*phi(eta)^2),eta):
rhop:=3880:
rhobf:=998.2:
cp:=773:
cbf:=4182:
rho:=unapply(  phi(eta)*rhop+(1-phi(eta))*rhobf ,eta):
c:=unapply(  (phi(eta)*rhop*cp+(1-phi(eta))*rhobf*cbf )/rho(eta) ,eta):
mu_phi:=mu1[bf]*(a[mu1]+2*b[mu1]*phi(eta)):
gama1:=0.00:
a[mu1]:=39.11:
b[mu1]:=533.9:
mu1[bf]:=9.93/10000:
a[k1]:=7.47:
b[k1]:=0:
k1[bf]:=0.597:
zet:=1:
phi1[w]:=phi0:
mu1[w]:=mu(0):
k1[w]:=k(0):

eq1:=subs(phi(0)=phi0,eq1);
eq2:=subs(phi(0)=phi0,eq2);
eq3:=subs(phi(0)=phi0,eq3);
/  d   /  d         \\   //                                    
|----- |----- u(eta)|| + \\0.0009930000000 + 0.03883623000 phi0
\ deta \ deta       //                                         

                      2\                                 
   + 0.5301627000 phi0 / (sigma - 500 phi(eta) + 500 phi0

                           \//               
   - (1 - phi(eta)) T(eta))/ \0.0009930000000

                                                   2\   
   + 0.03883623000 phi(eta) + 0.5301627000 phi(eta) / +

  /                                       /  d           \ /  d  
  |(0.03883623000 + 1.060325400 phi(eta)) |----- phi(eta)| |-----
  \                                       \ deta         / \ deta

         \\//                                        
   u(eta)|| \0.0009930000000 + 0.03883623000 phi(eta)
         //                                          

                          2\
   + 0.5301627000 phi(eta) /
           /  d         \     0.597 + 4.45959 phi0  
           |----- T(eta)| - ------------------------
           \ deta       /   0.597 + 4.45959 phi(eta)
                                        /  d         \
                            1. phi(eta) |----- T(eta)|
         /  d           \               \ deta       /
         |----- phi(eta)| - --------------------------
         \ deta         /                           2
                             0.5 cc + 0.75 - 0.75 cc  
Q:=proc(pp2,fi0) option remember; local res,F0,F1,F2,a,INT0,INT10,B;
print(pp2,fi0);
if not type([pp2,fi0],list(numeric)) then return 'procname(_passed)' end if;
res := dsolve(subs(sigma=pp2,phi0=fi0,{eq1=0,eq2=0,eq3=0,u(1)=-lambda*D(u)(1),u(0)=lambda*D(u)(0),phi(0)=phi0,T(0)=0}), numeric,output=listprocedure,initmesh=10, continuation=cc);
F0,F1,F2:=op(subs(res,[u(eta),phi(eta),T(eta)]));
INT0:=evalf(Int((abs(F0(eta)),eta=0..1)));
INT10:=evalf(Int(abs(F0(eta))*F1(eta),eta=0..1));
a[1]:=evalf(Int(F0(eta)*(F1(eta)*rhop+(1-F1(eta))*rhobf),eta=0..1));
#a[1]:=evalf(Int((F0(eta),eta=0..1)));
a[2]:=(INT10/INT0-Phiavg)/Phiavg; #relative
[a[1],a[2]]
end proc:
Q1:=proc(pp2,fi0) Q(_passed)[1] end proc;
Q2:=proc(pp2,fi0) Q(_passed)[2] end proc;
proc(pp2, fi0)  ...  end;
proc(pp2, fi0)  ...  end;
#Q(116,0.0041);
#tempe:=Optimization:-LSSolve([Q1,Q2],initialpoint=[130,0.01]);
#tempe:=Optimization:-LSSolve([Q1,Q2],initialpoint=[43.55,0.39]);
tempe:=Optimization:-LSSolve([Q1,Q2],initialpoint=[5.65,0.00036]);
#tempe:=Optimization:-LSSolve([Q1,Q2],initialpoint=[12,0.003]); # khoob ba 1
#tempe:=Optimization:-LSSolve([Q1,Q2],initialpoint=[5,0.01]);
                  HFloat(5.65), HFloat(3.6e-4)
           HFloat(5.650000070103341), HFloat(3.6e-4)
           HFloat(5.65), HFloat(3.600105456508193e-4)
     HFloat(29.63242379055208), HFloat(0.0205927592420527)
    HFloat(12.803902258015825), HFloat(0.006395385884750864)
    HFloat(12.803902403534572), HFloat(0.006395385884750864)
    HFloat(12.803902258015825), HFloat(0.00639539649402585)
   HFloat(12.804004931505949), HFloat(0.0063954867657199386)
    HFloat(12.804107604996073), HFloat(0.006395587646689013)
    HFloat(12.80400483062498), HFloat(0.006498160255844027)
    HFloat(12.803902157134855), HFloat(0.006498059374874952)
   HFloat(-1.0206939292143726), HFloat(-3.32764179807047e-4)
   HFloat(-1.0206939079125088), HFloat(-3.32764179807047e-4)
   HFloat(-1.0206939292143726), HFloat(-3.327536344433438e-4)
    HFloat(18.749500943683863), HFloat(0.01993840615828979)
    HFloat(3.9953780262640484), HFloat(0.00481041471606933)
     HFloat(6.166152606930136), HFloat(0.00703619658484674)
    HFloat(7.3193201827812295), HFloat(0.008218585352824569)
Error, (in Optimization:-LSSolve) complex value encountered
sigma:=tempe[2](1);
                          tempe[2](1)
phi0:=tempe[2](2);
                          tempe[2](2)
with(plots):

res2 := dsolve({eq1=0,eq2=0,eq3=0,u(1)=-lambda*D(u)(1),u(0)=lambda*D(u)(0),phi(0)=phi0,T(0)=0}, numeric,output=listprocedure,continuation=cc);
Error, (in dsolve/numeric/process_input) boundary conditions specified at too many points: {0, 1, 2}, can only solve two-point boundary value problems
G0,G1,G2:=op(subs(res2,[u(eta),phi(eta),T(eta)])):
ruu:=evalf((Int(abs(G0(eta))*(G1(eta)*rhop+(1-G1(eta))*rhobf ),eta=0..zet)))/(Phiavg*rhop+(1-Phiavg)*rhobf);
phb:=evalf((Int(abs(G0(eta))*G1(eta),eta=0..1))) / evalf((Int(abs(G0(eta)),eta=0..1))) ;
TTb:=evalf(Int(abs(G0(eta))*G2(eta)*(G1(eta)*rhop*cp+(1-G1(eta))*rhobf*cbf ),eta=0..1))/evalf(Int(abs(G0(eta))*(G1(eta)*rhop*cp+(1-G1(eta))*rhobf*cbf ),eta=0..1));
Error, invalid input: subs received res2, which is not valid for its 1st argument
                /  /1.                                        \
                | |                                           |
0.0008538922115 | |    |G0(eta)| (2881.8 G1(eta) + 998.2) deta|
                | |                                           |
                \/0.                                          /
                    /1.                       
                   |                          
                   |    |G0(eta)| G1(eta) deta
                   |                          
                  /0.                         
                  ----------------------------
                        /1.                   
                       |                      
                       |                      
                       |    |G0(eta)| deta    
                      /                       
                       0.                     
                                                              /Int(
                              1                               |     
------------------------------------------------------------- |     
  /1.                                                         |     
 |                                                            \     
 |              /             6                       6\            
 |    |G0(eta)| \-1.1752324 10  G1(eta) + 4.1744724 10 / deta       
/                                                                   
 0.                                                                 

                    /             6                       6\ , eta = 0. .. 1.)
  |G0(eta)| G2(eta) \-1.1752324 10  G1(eta) + 4.1744724 10 /                  

  \
  |
  |
  |
  /
#rhouu:=evalf((Int((G1(eta)*rhop+(1-G1(eta))*rhobf)*G0(eta),eta=0..1)));

odeplot(res2,[[eta,u(eta)/ruu],[eta,phi(eta)/phb],[eta,T(eta)/TTb]],0..1);
#odeplot(res2,[[eta,u(eta)],[eta,phi(eta)],[eta,T(eta)]],0..1);
Error, (in plots/odeplot) input is not a valid dsolve/numeric solution
rhou:=evalf((Int(abs(G0(eta))*(G1(eta)*rhop+(1-G1(eta))*rhobf ),eta=0..zet))):

Nub:=(1/G2(1))*(((1+a[k1]*abs(G1(0))+b[k1]*abs(G1(0))^2)/(1+a[k1]*Phiavg+b[k1]*Phiavg^2)));
                0.6905123602 (1 + 7.47 |G1(0)|)
                -------------------------------
                             G2(1)             
(rhs(res2(0.0000000000001)[3])-rhs(res2(0)[3]))/0.0000000000001;
Error, invalid input: rhs received res2(0.1e-12)[3], which is not valid for its 1st argument, expr
sigma;
                          tempe[2](1)
NBT;
                              0.5
>

 

the above code has been worked for NBT=0.6 and higher, whereas as NBT decreases, the code doesnt converge easily.

How can I fix this problem?

Thanks for your attention in advance

Amir

I'm trying to model a simple pendulum. I have arrived at this code which gives me an animation of a point swinging.

 

 

To analyse the pendulum I want to plot a graph of phi against time, but do not know how to take readings from my animation to plot a graph with.

Thanks.

Hello,

I was wondering how (or what is the best way) to write a worksheet in which a change of formula is used when a certain value on the y-axis is reached.

So for example: if there is a mass-spring system with damping in it, I would like to change the value of the damping when the displacement/velocity/acceleration has reached a certain value.
So when I apply a force to the mass-spring system, and the acceleration for example is LOWER than 0.2 m/s^2 I use a value of X % damping, but when the value of the acceleration is HIGER than 0.2 m/s^2 I want to apply Y % damping. So in time the curve will increase (when low damping is used) and the curve will decrease (because high damping is used, because the y-value is higher than 0.2 m/s^2), and so on...

I hope somebody has a 'simple' idea. I know what I want to do, but I don't know how to put this down in a formula which I can write in Maple.

Greetings,
Frank

Hi everyone,

I have a very complicated function y with only one independent variable x, and want to fit or approximate it by a simpler function, say polynomial. Many books or maple reference seem to tell how to fit a set of data instead of a given function. But the argument x in the function is assumed to be continuous other than discrete, so I don't know whether it is possible to express datax in form of x's range such as 0..1, and express datay in form of the function. After that , maybe I can fit the two created data sets by a polynomial function.

Or, does anyone have a better or more direct way to do the fitting linking two fucntions?

I am appreciated for your help.

Best,

GOODLUCK

hello. before I used Mapple 15. But then I`ve run Mapple 16 and now I`ve a problem. I can`t use this program. I open the program, everthing is in the rule, but if I want to write any mathemathical function, or a letter, such as- x or x+2, the program does`t give any reaction. program only gives reaction the numbers.

Please, help me. (my english isn`t very good, and I don`t know I`ve explained my opinion).

Hi,

I get the error in the following code

restart:

gama1:=0.01:

zet:=0;
#phi0:=0.00789:
Phiavg:=0.02;
lambda:=0.01;
Ha:=1;


                               0
                              0.02
                              0.01
                               1
rhocu:=2/(1-zet^2)*int((1-eta)*rho(eta)*c(eta)*u(eta),eta=0..1-zet):

eq1:=diff(u(eta),eta,eta)+1/(mu(eta)/mu1[w])*(1-Ha^2*u(eta))+((1/(eta)+1/mu(eta)*(mu_phi*diff(phi(eta),eta)))*diff(u(eta),eta));
eq2:=diff(T(eta),eta,eta)+1/(k(eta)/k1[w])*(-2/(1-zet^2)*rho(eta)*c(eta)*u(eta)/(p2*10000)+( (a[k1]+2*b[k1]*phi(eta))/(1+a[k1]*phi1[w]+b[k1]*phi1[w]^2)*diff(phi(eta),eta)+k(eta)/k1[w]/(eta)*diff(T(eta),eta) ));
eq3:=diff(phi(eta),eta)+phi(eta)/(N[bt]*(1+gama1*T(eta))^2)*diff(T(eta),eta);
      /  d   /  d         \\   mu1[w] (1 - u(eta))
      |----- |----- u(eta)|| + -------------------
      \ deta \ deta       //         mu(eta)      

           /             /  d           \\               
           |      mu_phi |----- phi(eta)||               
           | 1           \ deta         /| /  d         \
         + |--- + -----------------------| |----- u(eta)|
           \eta           mu(eta)        / \ deta       /
                                /      /                        
                                |      |                        
/  d   /  d         \\     1    |      |  rho(eta) c(eta) u(eta)
|----- |----- T(eta)|| + ------ |k1[w] |- ----------------------
\ deta \ deta       //   k(eta) |      |         5000 p2        
                                \      \                        

                                /  d           \
     (a[k1] + 2 b[k1] phi(eta)) |----- phi(eta)|
                                \ deta         /
   + -------------------------------------------
                                          2     
         1 + a[k1] phi1[w] + b[k1] phi1[w]      

            /  d         \\\
     k(eta) |----- T(eta)|||
            \ deta       /||
   + ---------------------||
           k1[w] eta      ||
                          //
                                      /  d         \
                             phi(eta) |----- T(eta)|
          /  d           \            \ deta       /
          |----- phi(eta)| + ------------------------
          \ deta         /                          2
                             N[bt] (1 + 0.01 T(eta))
mu:=unapply(mu1[bf]*(1+a[mu1]*phi(eta)+b[mu1]*phi(eta)^2),eta):
k:=unapply(k1[bf]*(1+a[k1]*phi(eta)+b[k1]*phi(eta)^2),eta):
rhop:=3880:
rhobf:=998.2:
cp:=773:
cbf:=4182:
rho:=unapply(  phi(eta)*rhop+(1-phi(eta))*rhobf ,eta):
c:=unapply(  (phi(eta)*rhop*cp+(1-phi(eta))*rhobf*cbf )/rho(eta) ,eta):
mu_phi:=mu1[bf]*(a[mu1]+2*b[mu1]*phi(eta)):

a[mu1]:=39.11:
b[mu1]:=533.9:
mu1[bf]:=9.93/10000:
a[k1]:=7.47:
b[k1]:=0:
k1[bf]:=0.597:
zet:=0.5:
#phi(0):=1:
#u(0):=0:
phi1[w]:=phi0:
N[bt]:=0.2:
mu1[w]:=mu(0):
k1[w]:=k(0):

eq1:=subs(phi(0)=phi0,eq1):
eq2:=subs(phi(0)=phi0,eq2):
eq3:=subs(phi(0)=phi0,eq3):

#A somewhat speedier version uses the fact that you really need only compute 2 integrals not 3, since one of the integrals can be written as a linear combination of the other 2:
Q:=proc(pp2,fi0) local res,F0,F1,F2,a,INT0,INT10,B;
global Q1,Q2;
print(pp2,fi0);
if not type([pp2,fi0],list(numeric)) then return 'procname(_passed)' end if:
res := dsolve(subs(p2=pp2,phi0=fi0,{eq1=0,eq2=0,eq3=0,u(1)=lambda/(phi(1)*rhop/rhobf+(1-phi(1)))*D(u)(1),D(u)(0)=0,phi(1)=phi0,T(1)=0,D(T)(1)=1}), numeric,output=listprocedure):
F0,F1,F2:=op(subs(res,[u(eta),phi(eta),T(eta)])):
INT0:=evalf(Int((1-eta)*F0(eta),eta=0..1-zet));
INT10:=evalf(Int((1-eta)*F0(eta)*F1(eta),eta=0..1-zet));
B:=(-cbf*rhobf+cp*rhop)*INT10+ rhobf*cbf*INT0;
a[1]:=2/(1-zet^2)*B-10000*pp2;
a[2]:=INT10/INT0-Phiavg;
Q1(_passed):=a[1];
Q2(_passed):=a[2];
if type(procname,indexed) then a[op(procname)] else a[1],a[2] end if
end proc;
#The result agrees very well with the fsolve result.
#Now I did use a better initial point. But if I start with the same as in fsolve I get the same result in just about 2 minutes, i.e. more than 20 times as fast as fsolve:

Q1:=proc(pp2,fi0) Q[1](_passed) end proc;
Q2:=proc(pp2,fi0) Q[2](_passed) end proc;
Optimization:-LSSolve([Q1,Q2],initialpoint=[6.5,exp(-1/N[bt])]);


proc(pp2, fi0)  ...  end;
proc(pp2, fi0)  ...  end;
proc(pp2, fi0)  ...  end;
              HFloat(6.5), HFloat(0.006737946999)

 

 

the error is :

Error, (in Optimization:-LSSolve) system is singular at left endpoint, use midpoint method instead

how can I fix it.

Thanks

 

Amir

Or I didn't get something right? This is with Maple 16.02 on a Mac:

maple worksheet snapshot

 

> for i from 1 to 10 while i<=5 do print(i) end do; #works all right
> for i from 1 to 10 while i>=5 do print(i) end do; #nothing shows up?

I'm trying to solve the following inequality:

ln(x+1)<x^2-1

but the solve command returns:

"Warning, solutions may have been lost"

Can someone help me?

Thank you.

Carmelita

I'm trying to solve the following inequality:

ln(x+1)<x^2-1

but the solve command returns:

"Warning, solutions may have been lost"

Can someone halp me?

Thank you.

Carmelita

When you use the slider without Do(%MathContainer1 = StandardError(Variance, R)):
everything works ok but when you add Do(%MathContainer1 = StandardError(Variance, R)):
Maple Crashes.....

Strange...

LL_102)_Covariance_M.mw

How can I get the Standard Errors of the covariance matrix in Maple?
I can simulate a covariance matrix in Maple as follows:

restart:
with(Statistics):
with(LinearAlgebra):

R := RandomMatrix(4, 4, generator = -15 .. 15, outputoptions = [datatype = float[8]]);
CovarianceMatrix(R);

but how do I find the standard errors?

I write this system but I have 2 error

 

restart; params := [z = 0,

Omega = 2.2758,

tau = 13.8, T2 = 200,

omega0 = 1,

r = .7071,

s = 2.2758,

omega = .5]

 

sys1 := {diff(q(t), t) = -2*Omega*v(t)-s*exp(-r^2/omega0^2-t^2*1.177^2/tau^2)*cos(k*z-omega*t)*(y(t)-x(t))-q(t)/T2,

diff(v(t), t) = Omega*q(t)-v(t)/T2,

diff(x(t), t) = 2*s*exp(-r^2/omega0^2-t^2*1.177^2/tau^2)*cos(k*z-omega*t)*q(t)+y(t)/T1,

diff(y(t), t) = -2*s*exp(-r^2/omega0^2-t^2*1.177^2/tau^2)*cos(k*z-omega*t)*q(t)-y(t)/T1};

ICs1 := {q(-20) = 0, v(-20) = 0, x(-20) = 1, y(-20) = 0}

 

 

ans1 := dsolve(`union`(eval(sys1, params), ICs1), numeric, output = listprocedure); plots:-odeplot(ans1, [[t, x(t)], [t, y(t)], [t, q(t)], [t, v(t)]], t = -20 .. 20, legend = [x, y, q, v])

 

Error, invalid input: eval received params, which is not valid for its 2nd argument, eqns
Error, (in plots/odeplot) input is not a valid dsolve/numeric solution

Hello everybody

I'm new at using Maple

so what I'm trying to do is " solve system of differential equations numerically " and plot the result 

I use the floweing code

 

PDEtools[declare]((u, v, w)(t), prime = t)

> params := z = 0;

Omega= 2.2758;

tau = 13.8;

T2 = 200; s = 1;

r = 0.7071;

\[CapitalDelta] = 1.7758;

s = 2.2758;

Eta= 1.05457173*10^-34;

omega = 0.5; k = 1666666.667;

> sys1 := {diff(u(t), t) = Omega*v(t)-u(t)/T2,

diff(v(t), t) = -Omega*u*{t}-2*s*exp(-r^2/omega0^2-t^2*1.177^2/tau^2)*cos(k*z-omega*t)*w(t)-v(t)/T2,

diff(w(t), t) = 2*s*exp(-r^2/omega0^2-t^2*1.177^2/tau^2)*cos(k*z-omega*t)*v(t)};

Cs1 := {u(-20) = 0, v(-20) = 0, w(-20) = -1}

> ans1 := dsolve*RealRange(Open({ICs1, sys1}), {u(t), v(t), w(t)});
%;
Error, (in RealRange) invalid arguments

plot([u(t),t=-20..20])
plot([v(t),t=-20..20])
plot([w(t),t=-20..20])

 

 

:::::::::

also I need to use the result of v(t) in another equation as,

x=2*v(t)*cos(k*z-omega*t)

How I can do that ?

 

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