**Hi , everyone who love Maple and dsolve command, **

**my ODE is :**

sys_ode := diff(d11(m), m) = -(3*sin(m)^2-1)*d31(m)/a^(3/2)+(-3*cos(m)*sin(m)/a^(3/2))*d41(m), diff(d21(m), m) = (-3*cos(m)*sin(m)/a^(3/2))*d31(m)-(3*cos(m)^2-1)*d41(m)/a^(3/2), diff(d31(m), m) = -a^(3/2)*d11(m), diff(d41(m), m) = -a^(3/2)*d21(m)

**using** " dsolve([sys_ode]) "** command could get the solution easily, and the solution contains "I" (imaginary domain).**

**H***o*wever, when we substitute the solution into the ODE "sys_ode", find not correct !

**we use the following command to check the solution :**

simplify( -diff(d11(m), m) -(3*sin(m)^2-1)*d31(m)/a^(3/2)+(-3*cos(m)*sin(m)/a^(3/2))*d41(m) )

**the upper expression is supposed to be zero, but not ! Is it a bug in Maple dsolve ?**