אנרגיות...
E=U+K K-kinetic energy U-the potential energy K=m(dx/dt)^2/2 dx/dt=2sqrt((E-U)/m) dx/(2sqrt((E-U)/m)=dt integrate between t=0 until t=T where T is the period time, and equate E-U=0 to find the roots of this equations, you will find two roots, x=x1 and x=x2 integrate between them. change for the dx integration variables: ch(x)=y dy/sqrt(y^2-1)=dx you get: dy/2sqrt(E/m)sqrt((y^2-1)(y^2+U0/E)) Now in the sqrt you get y^4+(U0/E-1)y^2+(U0/E)^2 now try to complete it to a square form, i.e to get something like (y^2+A)^2+B, again redefine z=(y^2+A)/sqrt(B) dz=2ydy/sqrt(B) sqrt(B)dz/2sqrt((sqrt(B)z-A))=dy yuo get something like dz/sqrt(z^2+1)sqrt(sqrt(B)z-A) Now use integration by parts, Sorry but I don't plan to continue from here, cause I myself have HW.