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Differential equation

  1. Nov 1, 2009 #1
    any suggestions to solve the follows differential equations by using maple???

    see adjoint figure
     

    Attached Files:

  2. jcsd
  3. Nov 2, 2009 #2
    There are three function in your system of two ODEs. If a(t) and f(t) are unknown functions then you can proceed in Maple by following way

    AN:=dsolve({ec1,ec2},{a(t),f(t)});

    ans:={op(1,op(1,AN)),simplify(eval(subs(op(1,AN),op(1,op(2,AN)))),symbolic)};

    odetest(ans,{ec1,ec2});
     
  4. Nov 2, 2009 #3
    Thanks, but at last I find :
    " > odetest(ans, {ec1, ec2})

    Error, (in odetest) invalid input: odetest expects its 1st argument, SOL, to be of type {algebraic, `=`, set(`=`), list({`=`, set(`=`)})}, but received {o*p(1, {a(t) = -ln(2)+A(t)+2*ln(_C2)+I*Pi}), f(t) = Int(exp(1/2*A(t))*_C2/(exp(3*A(t))*_C1-2)^(1/2), t)+_C3}"
     
    Last edited: Nov 2, 2009
  5. Nov 2, 2009 #4
    Unfortunately, as I understand, there is the misprint in your (and mine) input in ans line

    ans:={op(1,op(1,AN)),simplify(eval(subs(op(1,AN),o p(1,op(2,AN)))),symbolic)};

    (o p reads as o*p)
    but must be

    ans:={op(1,op(1,AN)),simplify(eval(subs(op(1,AN), op(1,op(2,AN)))),symbolic)};

    P.S. It is funny, but this misprint appears in Post saving process of this site, so I was forced to insert space in front of op, but here it does not affect on Maple code!
     
    Last edited: Nov 2, 2009
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