Let f be a meromorphic non-entire function in the plane, and suppose that for every n ≥ 0, the derivative f(n) has only real zeros. We have proved that then f is rational and of a special form, and that all possibilities can be listed. In this paper we prove that part of this result which is related to properties of strictly non-real functions.
|Original language||English (US)|
|Number of pages||36|
|Journal||Annales Academiae Scientiarum Fennicae Mathematica|
|State||Published - Dec 1 1997|
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