@Jjjones98 There is no two-sided (forward) laplace transform in inttrans. Not sure what the two-sided inverse laplace would be, since the contour already runs g-I*infinity to g+I*infinity.

If I change the last line to have i = 0 .. 200, 100 then I get a list of 3 numbers as expected (after about 45 seconds). I'm guessing it could be made more efficient by implementing the trapezoidal rule (or similar) for your integrals.

Of course I didn't guess. Nice implementation of a spigot algorithm.

@Jjjones98 invfourier(expr, w , t) doesn't make sense if expr contains t; you would be going from the time domain to the time domain.

@Jjjones98 So invfourier cannot evaluate it, without more information, perhaps specifying values of some constants. Working with any expression that has general roots of a quartic polynomial will be almost impossible. But something is very strange since you inverse laplaced into the time demain and then inverse Fourier from an expression with t in it, into another time domain. ??

@Jjjones98 This is the same file as the original.

@Jjjones98 yes, there is invfourier. See ?inttrans for help on the different forward and inverse transforms.

@NaeemQau I don't have Maple 2019, so can't reproduce the error. But with the second set of parameters you don't see the error, so why not work from there and provide an approximate solution.

@NaeemQau At least in Maple 2017, the error is Error, (in dsolve/numeric/BVPSolve) initial Newton iteration is not converging. You should be able to find alpha with the extra boundary condition. I would back off on the accuracy conditions - Digits :=10 and a low abserr, and provide a simple initial guess (usually just the right general shape will do) using the appoxsoln option, based on what you think the solution looks like, When you can get some inaccurate solution, you can refine it.

@acer  Thanks. At the time I responded I could not see any other replies even though I refreshed the browser - this delay seems to be a random problem with Mapleprimes or perhaps my system.

Probably some parameter name doesn't have a value, but if you upload your worksheet with the green up arrow, someone can help you diagnose it.

@TeyhaNeedHelp Use * to enter multiplication, and give values to all parameters.

dsolve.mw

@Mohamed19 If you want something for general _k1, _k3, I don't think you'll get it, since any formula with an unspecified order of differentiation will be hard to deal with. If you use specific _k1,_k3, then you can evaluate and then convert. You can try the general case with convert.

I tried a few conversions, such as convert(  ,binomial) without success, but you could try some others.

@Adam Ledger In windows you can right-click on the .dll and choose properties. There is some information there, which may or may not have the authors etc; that depends on the .dll author.

@Mohamed19 I don't understand. Can you give an example of what you want as an answer.