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Question: Fourier Transforms

Question:Fourier Transforms

John Eric 80 Maple
dsolve numeric
November 09 2016
0

Dear all,

I need to transforme these equation from time domain to frequency domain with fourier transforms and solve it in frequency domain but i received the flowing error

any helps

thank you !

 

``

> 

restart:with(inttrans):
> 

E:=1;L:=1;

1

  

1

 (1)
> 

 

> 

equ := arccos(y(t)/R)*R*L*(diff(y(t), `$`(t, 1)))*abs(diff(y(t), `$`(t, 1)))+diff(y(t), `$`(t, 2))+m*sin(omega*t+k*R*sin(`θl`))+arccos(y(t)/R);

arccos(y(t)/R)*R*(diff(y(t), t))*abs(diff(y(t), t))+diff(diff(y(t), t), t)+m*sin(omega*t+k*R*sin(`θl`))+arccos(y(t)/R)

 (2)
> 

eq:=fourier(equ,t,omega);

((1/2)*I)*m*fourier(exp(-I*omega*t), t, omega)*exp(-(1/2)*k*R*exp(I*`θl`)+(1/2)*k*R*exp(-I*`θl`))-omega^2*fourier(y(t), t, omega)-((1/2)*I)*m*fourier(exp(I*omega*t), t, omega)*exp((1/2)*k*R*exp(I*`θl`)-(1/2)*k*R*exp(-I*`θl`))+R*fourier(arccos(y(t)/R)*(diff(y(t), t))*abs(diff(y(t), t)), t, omega)+fourier(arccos(y(t)/R), t, omega)

 (3)
> 

csi := y(0) = 0.2e-1, (D(y))(0) = 0;

y(0) = 0.2e-1, (D(y))(0) = 0

 (4)
> 

sol := dsolve({csi, eq}, numeric, maxfun = 1000000000)

Warning, The use of global variables in numerical ODE problems is deprecated, and will be removed in a future release. Use the 'parameters' argument instead (see ?dsolve,numeric,parameters)

  

Error, (in solve) cannot solve expressions with fourier(arccos(Y[1]/R)*YP[1]*abs(YP[1]), t, omega) for YP[1]

  

Code :

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