# Question: weird error that I don't understand

February 01 2013 by
false

0

Hi in trying to solve these coupled differential equations i get a weird error:

> t := diff(X(x), x) = -(1-6*R(x)^(1/2))^(1/2)*x*X(x)/(X(x)*x+R(x))^(1/2), diff(R(x), x) = (1-6*R(x)^(1/2))^(1/2)*x^2*X(x)/(X(x)*x+R(x))^(1/2);                                        (1/2)                                /          (1/2)\                         d           \1 - 6 R(x)     /      x X(x)            --- X(x) = - -----------------------------,            dx                             (1/2)                                  (X(x) x + R(x))                                                    (1/2)                               /          (1/2)\       2                  d         \1 - 6 R(x)     /      x  X(x)            --- R(x) = ------------------------------             dx                            (1/2)                                 (X(x) x + R(x))          > init(R(0) = 0, X(0) = 100);                   init(R(0) = 0, X(0) = 100)> Solve({t, init});Error, (in PDEtools:-casesplit) the input system cannot contain equations in the arbitrary parameters alone; found equation: init

I am using PDE tools, please can someone help.