Published online by Cambridge University Press: 14 February 2012
Let the coefficient q be real-valued on the half-line [0, ∞) and let q′ be locally absolutely continuous on [0, ∞). The ordinary symmetric differential expressions M and M2 are determined by
It has been shown in a previous paper by the authors that if for non-negative numbers k and X the coefficient q satisfies the condition
then M is limit-point and M2 is limit–2 at ∞.
This paper is concerned with showing that for powers of the independent variable x the condition (*) is best possible in order that both M and M2 should have the classification at ∞ given above.