Thanks for your answer.

Here are the three equations of my system. Unknowns are f(t), g(t) and h(t). invh is the inverse of h(t), invg is the inverse of g(t).

eq1:= (1.5*f(t) - t)*(diff(g(t),t)*h(t) + diff(h(t),t)*g(t))=g(t)*h(t);

eq2:= (1.5*g(t) - t)*(diff(f(t),t)*h(t) + diff(h(t),t)*f(t))-f(t)*h(t) + (g(t) - 1.5*g(t))*g(invh(g(t)))*f(invh(g(t)))*diff(f(t),t)=0;

eq3:= (1.5*h(t) - t)*(diff(g(t),t)*f(t) + diff(f(t),t)*g(t))-f(t)*g(t) + (h(t) - 1.5*h(t))*f(invg(h(t)))*(diff(g(t),t)*f(t)+diff(f(t),t)*g(t))=0;

Thanks for your answer.

Here are the three equations of my system. Unknowns are f(t), g(t) and h(t). invh is the inverse of h(t), invg is the inverse of g(t).

eq1:= (1.5*f(t) - t)*(diff(g(t),t)*h(t) + diff(h(t),t)*g(t))=g(t)*h(t);

eq2:= (1.5*g(t) - t)*(diff(f(t),t)*h(t) + diff(h(t),t)*f(t))-f(t)*h(t) + (g(t) - 1.5*g(t))*g(invh(g(t)))*f(invh(g(t)))*diff(f(t),t)=0;

eq3:= (1.5*h(t) - t)*(diff(g(t),t)*f(t) + diff(f(t),t)*g(t))-f(t)*g(t) + (h(t) - 1.5*h(t))*f(invg(h(t)))*(diff(g(t),t)*f(t)+diff(f(t),t)*g(t))=0;