I don't understand what did I do wrong with latex syntax.
If someone doesn't understand what I wrote:
m*x''(t)=-c/x(t)^2
I don't understand something, if you have a harmonic oscilator differential equation:
x''(t)+a^2*x(t)=0,
the solution is:
x(t)=Acos(a*t)+Bsin(a*t).
So why don't you get solution x(t)? Or do you suggest that solution is:
x(t)=c1+c2*t+c/m*ln(t) ?
If so, I don't think that's a solution, try puting it in initial equation.