Limit of function roots

[man111]

If [tex]f''(x)=(x^5+kx^3+1)f(x)[/tex] and [tex]f(0)=1,f'(0)=0[/tex] and [tex]\{a_{1},a_{2},.......a_{n}\}[/tex] be the set of all roots of [tex]f(x)=0[/tex], Then [tex]\lim_{n\rightarrow \infty}\min\{a_{1},a_{2},.......a_{n}\}[/tex] and [tex]\lim_{n\rightarrow \infty}\max\{a_{1},a_{2},.......a_{n}\}[/tex]