@Rouben Rostamian  

It's time to go about it so you don't get far behind the competition like another software aka: Mathematica,COSMOL,Matlab

@rlopez 

And when we see  a numeric elliptic solver in Maple.?

@Carl Love 

Yes ,you are absolutey right,Mathematica can't also expand derivatives.

Form here: http://functions.wolfram.com/HypergeometricFunctions/HypergeometricU/20/01/01/

we see that for: a parameter first derivative does not exist a closed-form solution.

@Shaaban 

In Mathematica 12.1 HypergeometricU[1, 1, x] is the same as KummerU(1,1,x) in Maple.

@muioxygen 

If you want save files *.mws to hard drive then: right click and save target as:

With complicated function probably only hope to get answer is use evalf(Int).

@Christopher2222 

and aac,opus format.

@Thomas Dean 

Code not work's for 2 variable?

@permanoon123 

See attached file.

Integral_new.mw

Maple can't solve PDE with numerics.

@JonMcLoone 

When will we see the version 12.1 ?

Mathematica have only up to 2*10^14.

@mahmood1800 

For first question:

You have 6  conditions:

1. f3(0,t)=-exp(-2*t)

2. f4(x,0)=exp(-3*x)*cos(2*Pi*x)

3. f1(x,3)=0

4. f1(3,t)=0

5. f2(x,3)=0

6. f2(3,t)=0

and we have a  5 constants,one condition is too much.

For second question:

No,is not true and not allowed.

Regards M.I

@aabdulla 

I don't know the answer to your question. I'm just a regular user, not a MAPLE developer.

@aabdulla 

With corrected syntax I able to solve integral with Maple.

See attached file.

Integrals_Sheet2-BB.mw