i am looking for the solution of diff equation: g*m*cos(v)+(h/sqrt(h^2+d^2)-1)*k*cos(v)+m*'diff(d,t,2)=sin(w*t)*cos(w*t= )*cos(v); were: cos(v)=cos(atang(d/h)); and: g,m,h,k are know, i am interesting in the solution in d for w=0,2 and t=0,10 thank to all hugo