Criteria for global asymptotic stability of a null solution
of a nonlinear differential equation of fifth order with delay%
begin{eqnarray*}
&&x^{(5)}(t)+psi (x(t-r),x^{prime }(t-r),x^{prime prime
}(t-r),x^{prime
prime prime }(t-r),x^{(4)}(t-r))x^{(4)}(t) \
&&quad+f(x^{prime prime }(t-r),x^{prime prime prime }(t-r))+alpha
_{3}x^{prime prime }(t)+alpha _{4}x^{prime }(t)+alpha _{5}x(t)=0
end{eqnarray*}
are obtained by using Lyapunov\u27s second method. By defining a
Lyapunov functional, sufficient conditions are established, which
guarantee the null solution of this equation is globally
asymptotically stable. Our result consists of a new theorem on the
subject