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Question: Why my eval command not apply ? and How i can get zero when i substitute function and parameter?

Question:Why my eval command not apply ? and How i can get zero when i substitute function and parameter?

salim-barzani 655 Maple
parameters eval substitution pde differential-equations duplicate-question incomplete-question
February 09 2025
0

i want to get zero of this function i did all part true but i don't know why my pde not getting zero after substitute each parameter and part 

> 

restart
> 

with(PDEtools)
> 

NULL
> 

undeclare(prime)

`There is no more prime differentiation variable; all derivatives will be displayed as indexed functions`

 (1)
> 

p := 2*k; n := 1; xi := -p*t+x

2*k

  

1

  

-2*k*t+x

 (2)
> 

"U(xi):=(B[1] (RootOf(3 _Z^2-3 _Z-1)+coth(xi)))^(-1/n);u(x,t):=(B[1] (RootOf(3 _Z^2-3 _Z-1)+coth(-p t+x)))^(-1/n) (e)^(ⅈ (k x-t w))"

proc (xi) options operator, arrow, function_assign; (B[1]*(RootOf(3*_Z^2-3*_Z-1)+coth(xi)))^(-1/n) end proc

  

proc (x, t) options operator, arrow, function_assign; (B[1]*(RootOf(3*_Z^2-3*_Z-1)+coth(-p*t+x)))^(-1/n)*exp(I*(k*x-t*w)) end proc

 (3)
> 

pde := I*(diff(u(x, t), t))+diff(u(x, t), `$`(x, 2))+eta*u(x, t)+beta*U(xi)^n*u(x, t)+gamma*U(xi)^(2*n)*u(x, t)+delta*U(xi)^(3*n)*u(x, t)+lambda*U(xi)^(4*n)*u(x, t) = 0

I*(2*exp(I*(k*x-t*w))*k*(1-coth(2*k*t-x)^2)/(B[1]*(RootOf(3*_Z^2-3*_Z-1)-coth(2*k*t-x))^2)-I*w*exp(I*(k*x-t*w))/(B[1]*(RootOf(3*_Z^2-3*_Z-1)-coth(2*k*t-x))))+2*exp(I*(k*x-t*w))*(1-coth(2*k*t-x)^2)^2/(B[1]*(RootOf(3*_Z^2-3*_Z-1)-coth(2*k*t-x))^3)-(2*I)*k*exp(I*(k*x-t*w))*(1-coth(2*k*t-x)^2)/(B[1]*(RootOf(3*_Z^2-3*_Z-1)-coth(2*k*t-x))^2)+2*exp(I*(k*x-t*w))*coth(2*k*t-x)*(-1+coth(2*k*t-x)^2)/(B[1]*(RootOf(3*_Z^2-3*_Z-1)-coth(2*k*t-x))^2)-k^2*exp(I*(k*x-t*w))/(B[1]*(RootOf(3*_Z^2-3*_Z-1)-coth(2*k*t-x)))+eta*exp(I*(k*x-t*w))/(B[1]*(RootOf(3*_Z^2-3*_Z-1)-coth(2*k*t-x)))+beta*exp(I*(k*x-t*w))/(B[1]^2*(RootOf(3*_Z^2-3*_Z-1)-coth(2*k*t-x))^2)+gamma*exp(I*(k*x-t*w))/(B[1]^3*(RootOf(3*_Z^2-3*_Z-1)-coth(2*k*t-x))^3)+delta*exp(I*(k*x-t*w))/(B[1]^4*(RootOf(3*_Z^2-3*_Z-1)-coth(2*k*t-x))^4)+lambda*exp(I*(k*x-t*w))/(B[1]^5*(RootOf(3*_Z^2-3*_Z-1)-coth(2*k*t-x))^5) = 0

 (4)
> 

case1 := [beta = 2*RootOf(3*_Z^2-3*_Z-1)*(n+2)/(B[1]*n^2), delta = 2*B[1]*(RootOf(3*_Z^2-3*_Z-1)+1)*(3*n+2)/(3*n^2), eta = (k^2*n^2*B[1]^2-n^2*w*B[1]^2-1)/(n^2*B[1]^2), gamma = -6*RootOf(3*_Z^2-3*_Z-1)*(n+1)/n^2, lambda = B[1]^2*(3*RootOf(3*_Z^2-3*_Z-1)-7)*(2*n+1)/(9*n^2), A[0] = RootOf(3*_Z^2-3*_Z-1)*B[1], A[1] = 0, B[1] = B[1]]

[beta = 6*RootOf(3*_Z^2-3*_Z-1)/B[1], delta = (10/3)*B[1]*(RootOf(3*_Z^2-3*_Z-1)+1), eta = (k^2*B[1]^2-w*B[1]^2-1)/B[1]^2, gamma = -12*RootOf(3*_Z^2-3*_Z-1), lambda = (1/3)*B[1]^2*(3*RootOf(3*_Z^2-3*_Z-1)-7), A[0] = RootOf(3*_Z^2-3*_Z-1)*B[1], A[1] = 0, B[1] = B[1]]

 (5)
> 

pde3 := eval(pde, case1)
 

``

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