@tomleslie tnx for your compelete answer

@tomleslie sorry for the inconvenience, you are right, but a1 is not constant and is a function of time, it is int(a1(t)*A(t),t)...
actually a1=(t)->(wl/gamma1)*cos(w*t);
can it be solved?

@tomleslie actually diff(x(t),t)=A(t) as u have defined, can i use directly A(t) ? even i used :
int(eval(A(t),ans),t=0..1); but it does not computed ...

odeProb.mw

@tomleslie i want to fit a function to these three plots...
i used polynomial interpolation (CurveFitting:-PolynomialInterpolation([seq]([t, (eval(B(t),ans))(t)],t=0.1..1,0.1),t)).
but it does not give the functions, i think it can be fitted using trigonomic functions, but actually i don't know how, could u help ?
and actually i want to calculate the integral :
int(a1*diff(x(t),t) +a2*diff(y(t),t)+a3*diff(z(t),t) );
can i calculate this without interpolating the functions? tnx for the help...
odeProb.mw

@tomleslie thanak you, and i made use of these deriavatives...

@tomleslie that was interesting idea ! tnx for the help ! Good Luck !

@Mariusz Iwaniuk tnx for your help,where in the help i can find answers for these questions? could please give me a link of the related halp page? tnx

@rlopez tnx for explanation, you are right sir

@tomleslie tnx for your answer,it was helpful, but under "Supplemental Software" there is NOT any help document for maple toolbox...
as u can see in the uploaded picture...
and for the prettyprint option, you say this is just a limitation of using maple in matlab and can not be cured right?

@saba you should specify boundary conditions and other constants and after that, i think you will get desired answer

@tomleslie i guess that the problem is with independent variables, i guess W and Phi are functions of both " x " and " z "

@torabi if it has phi(z) it is pde ! not ode ! but i assume you should define function of Z , as a parametr , then solve your equations and after that ! solve your pramater.

in your equation, phi is function of z ! but in intergal and thus should be solved ! and then you should solve your ode system ! 

@tomleslie 
https://en.wikipedia.org/wiki/Weighted_space

@tomleslie tnx for your help, but your answer is some what different from @Axel Vogt's answer ...