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NIMA112

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These are questions asked by NIMA112

verify two parameters are equal...

NIMA112 35 Maple 2020
integration simplification indexed
March 05 2024
0 1

Hello,

How I can show that the value of psi 1 through method #1 is equal to that one in method #2?

is possible to verify by analytic results, not using and placing parameter's numerical values?

show.mw

some parameters not considered in final ...

NIMA112 35 Maple 2020
parameters syntax 2dmath
February 25 2024
2 2

Hi.

why in eq1 some parameters such as beta 1, Q110,... are not placed (They defined before eq1 !!!!)

Thanks

TRASH.mw

nconsistency in starting the branches fr...

NIMA112 35 Maple 2023
integration contourplot plotting
December 07 2023
1 10

hi every one.

in the attached maple file at line x=o in the plotted figure we have some inconsistency in starting the branches from x=0 and the branches do not start from the same value on this axis.

I can not find the problem because there are not any differences between phi 1 and phi 2! 

evalf(f1 - f2)= -5* 10 ^-49

h-x_nemodar-e.mw

How do I solve differential equations in...

NIMA112 35 Maple 2020
homework pde numeric
November 30 2023
0 2

How I can solve a PDE on two regions with matching conditions at the common boundary?  

T1.mw

how I can find the solution of different...

NIMA112 35 Maple 2022
ode homework dsolve
November 09 2023
2 5

how I can find the solution of differential equations with dsolve?

Thesis_(1).mw

> 

restart
> 

``
> 

a := Pi; b := Pi; lambda := 0.1e-1; beta := 2.5; x[1] := -1; x[2] := 1; y[1] := 1.5; y[2] := 1.5; alpha := 1; Q[1] := 40; Q[2] := 35; n := 3

Pi

  

Pi

  

0.1e-1

  

2.5

  

-1

  

1

  

1.5

  

1.5

  

1

  

40

  

35

  

3

 (1)
> 

upsilon := (2*n-1)*Pi/(2*b)

5/2

 (2)
> 

EQ1 := diff(U[1, n](x), x, x)-upsilon^2*U[1, n](x) = -2*(int(Q[1]*Dirac(x-x[1])*Dirac(eta-y[1])*sin(upsilon*eta), eta = 0 .. b))/b

diff(diff(U[1, 3](x), x), x)-(25/4)*U[1, 3](x) = 14.55468946*Dirac(x+1.)

 (3)
> 

EQ2 := -(diff(U[2, n](x), x, x))-upsilon^2*U[2, n](x) = -2*(int(Q[2]*Dirac(x-x[2])*Dirac(eta-y[2])*sin(upsilon*eta), eta = 0 .. b))/b

-(diff(diff(U[2, 3](x), x), x))-(25/4)*U[2, 3](x) = 12.73535328*Dirac(x-1.)

 (4)
> 

``
> 

bc := limit(U[2, n](x), x = infinity) < infinity, alpha*(diff(U[1, n](-a), x))-beta*U[1, n](-a) = 0, U[1, n](0) = U[2, n](0), (D(U[1, n]))(0) = lambda*(D(U[2, n]))(0)

limit(U[2, 3](x), x = infinity) < infinity, -2.5*U[1, 3](-Pi) = 0, U[1, 3](0) = U[2, 3](0), (D(U[1, 3]))(0) = 0.1e-1*(D(U[2, 3]))(0)

 (5)
> 

dsys6 := {EQ1, EQ2, bc}

{-2.5*U[1, 3](-Pi) = 0, diff(diff(U[1, 3](x), x), x)-(25/4)*U[1, 3](x) = 14.55468946*Dirac(x+1.), -(diff(diff(U[2, 3](x), x), x))-(25/4)*U[2, 3](x) = 12.73535328*Dirac(x-1.), U[1, 3](0) = U[2, 3](0), (D(U[1, 3]))(0) = 0.1e-1*(D(U[2, 3]))(0), limit(U[2, 3](x), x = infinity) < infinity}

 (6)
> 

dsol6 := dsolve(dsys6, numeric)

Error, (in dsolve/numeric/process_input) system must be entered as a set/list of expressions/equations

  
> 

U[1](x, y) = sum(U[1, n](x)*sin(upsilon*y), n = 1 .. infinity)

Error, (in sum) summation variable previously assigned, 2nd argument evaluates to 3 = 1 .. infinity

  
> 

U[2](x, y) = sum(U[2, n](x)*sin(upsilon*y), n = 1 .. infinity)

Error, (in sum) summation variable previously assigned, 2nd argument evaluates to 3 = 1 .. infinity

  
> 

NULL

Download Thesis_(1).mw

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