Question: error after use ''for'' in program

hi..when i use rule [for] in maple code i encounter error'''''

Error, (in dsolve/numeric/process_input) input system must be an ODE system, found {f1(x), f2(x), f3(x), ApproximateInt(-4*cos(theta)^2, theta = 0. .. 1, method = simpson), ApproximateInt(4*cos(theta)^2, theta = 0. .. 1, method = simpson), ApproximateInt(8*cos(theta)^2, theta = 0. .. 1, method = simpson)}''''''''

please help me for remove it

99999999999999.mw

i want for different beta for example beta=0, 40 and 80 this lines will computed three times  

 ''with(Student[Calculus1]); a1 := ApproximateInt(g1*g1, theta = a .. 1, method = simpson); a2 := ApproximateInt(2*(g1*g1)+3*g1*(diff(g1, theta, theta)), theta = a .. 1, method = simpson).......................''          

 by {for i from 1 by 1 to 3 do } and final gain ''ITRA_1_W[m] := eval(fy33*g3, fixedparameter)'' that have 3 amount.

when i use  rule {for i from 1 by 1 to 3 do ...  }   integral not computed and showed for example:::

a1=ApproximateInt(4*cos(theta)^2, theta = 0. .. 1, method = simpson)!!!!!!!!

thanks..