BY-NC-NDĐurčić, DraganMitrović I.Janjić M.2020-09-192020-09-1920110354-5180https://scidar.kg.ac.rs/handle/123456789/9643In this paper we discuss the relationship between the weak and the strong asymptotic equivalence relation and the asymptotic inversion, for positive and measurable functions defined on a half-axis [a, + ∞) (a > 0). As the main results, we prove a certain characterizations of the functional class of all rapidly varying functions, as well as some other functional classes.openAccesshttps://creativecommons.org/licenses/by-nc-nd/4.0/article10.2298/FIL1104029D2-s2.0-79960818550