## 260 Reputation

10 years, 223 days

## Social Networks and Content at Maplesoft.com

PH.D in Applied Mathematics

## thanks...

dear M.I

thanks a lot again for your elegant guide. hope you all the best.

Dear Mariusz Iwaniuk

Thanks in advance for your great answer, but I have two question about it and i will be so grateful if you can guide me:

1. In the line "sol := pdsolve([PDE]);" we see 5 constants which should be detemined via BC's and IC's(Boundary and Initial Conditions). But we have only 4 of these conditions. So how we should match them?

2. In the line "SOL := solve.....eval(rhs(sol[1]),t=3)=0,", I have change "eval(rhs(sol[1]),t=3)=0" to eval(rhs(sol[1]),{x=3,t=3)=0". is this true for condition 3? Am I allowded?

Thanks again for any help

## @Carl Love Dear Carl LOve, Hi....

@Carl Love
Dear Carl LOve,
Hi. In the following code, I can see the general solution but i don't know how apply the initial conditions. also I want to know if there is any analytical solution to the problem using maple?

>restart;
> with(PDEtools):
>E1:=[ diff(f1(x,t),x)=2*f3(x,t)+3*f1(x,t)-f2(x,t),
diff(f2(x,t),t)=-2*f4(x,t)-3.2*f1(x,t)+f2(x,t),
diff(f3(x,t),x)=-3*f3(x,t)+3.2*f4(x,t)-0.045*f1(x,t),
diff(f4(x,t),t)=f3(x,t)-f4(x,t)];

>sol:=pdsolve(E1,[f1,f2,f3,f4]);

## apologize for the mistake in typing....

Hi Dera Kitonum

I apologize for the mistake in typing. Thank you for your complete response. I resubmitted the modified form of the problem. Thanks for the guidance again.

## apologize for the mistake in typing...

Hi Dear.

I apologize for the mistake in typing. The corrected problem has been replaced.

## correction...

Thank you dear Carl
A is also a column vector and I have forgotten the "T" superscript.

A and H(t) can have finite number of elements(say, n).

## @Rouben Rostamian   thanks in advan...

@Rouben Rostamian

@Kitonum

## correction...

Hi

Sorry, i have not seen the "=" sign. ok. so we have the constraint as "A=B+C", and if we change it to "A-B-C=0", then we could have following:

>restart;
> with(Optimization):
> with(plots):
>   obj := (c0-x)^2+(c1-(2/3)*x-(1/3)*y)^2+(c2-(1/3)*x-(2/3)*y)^2+(c3-y)^2;
>  cnsts := 32*x+19*y - 15*c0+18*c1+15*c2+3*c3;
>            Minimize(obj, {cnsts=0});
where we have

[0., [c0 = 0., c1 = 0., c2 = 0., c3 = 0., x = 0., y = 0.]]

but i am not sure that this is true.

## this is true...

Dear Kitonum
thanks in advance. the program is now works correctly. that is so great.
hope you the best.
mahmood

Dear Kitonum
thanks in advance. But this reduce the same polynomials for all the subintervals. this is not true.
hope you the best

## thanks...

@vv
thanks a lot

this is the corret code...

Best wishes

## correction...

Hi and thanks,

My main problem is the procedure that produce the bn,m(t)'s correctly. The Fourier coefficient associated to the restriction of x(t) will be found under some constraints later.

## Correction of question...

Hi, thanks...I have corrected my question.

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