Abstract:
This paper is devoted to studying on the locations of zeros of related integral operators and the solutions of some ordinary and fractional differential equations. We generalize Sturm and Picone's theorems and Leighton and Levin's criteria. Moreover, we share some oscillation and disconjugacy criteria for the solutions of ordinary second-order Sturm–Liouville and fractional differential equations. Finally, we introduce some properties of the solutions of fractional differential equations.