Dear Sirs, 
I was with my students today, and attempting to do a Math Maple exercise. The assignment contained the requirement to plot three graphs in one plot f,g,h. Those with windows pc and maple were able use the proper command. 

plot({f(x),g(x),h(x)}) or plot([f(x),g(x),h(x)])  however some of those with MacOS would inside Maple 2021 get an error which said "GNU compiler not found", when using the same command. For those there was no other way (that I knew off) than to do a 

p1:=plot(f(x)): 

p2:=plot(g(x)): 

p3:=plot(h(x)):

and then plots:-display([f(x),g(x),h(x)]):  which work.

But why the MacOS error ? Any idea?

Lets say I wanna write a procedure DrawSpaceCurve3d. 

DrawSpaceCurve3d:=proc(fnc::algebraic, vars:name,h::integer, xvalue::range=a{integer}...b..{integer})
plots:-spacecurve([vars, h, funk(vars, h)], ':-x' = 'xvalue')
end proc; 

How I try to run this procedure, then I get the following error. 

"Error, (in Plot:-SpaceCurve) parameter range in the form name=range is missing"

So my question is it possible to get Maple to accept that I write DrawSpaceCurve3D(x^2*y, 2, xvalue=[-5..5]) 

I know the y - curve is missing, but I would like to see if I can get Maple to accept this kind of input?
 

Is that possible ? Or do I need a seperate compiler?

If I am running Windows is there any way to make Maple see the directory of an external program like for instance Geogebra? 

I have tried with

file := fopen("inputfile.ggb",WRITE, TEXT);

execute; fprintf(file, "line((2,3),(4,6)\n");
close(file);
 system[launch]("Geogebra.exe testfile.ggb"); 

Where line is a command in Geogebra, to draw a straight line.  

But I get an error where Maple claims it cannot see Geogebra. 

Any idea how to fix this?  

If I have v = 2400000 m/s as a a result. 

How do I convert this with units to 2.4*10 m/s in maple. 

Any idea on howto do this?

Best Regards.