Volume 37 • Number 4 • 2014   • On Opial-Dan's Type Inequalities Zhao Chang-Jian and Wing-Sum Cheung Abstract. In the present paper we establish some new Opial-type inequalities involving higher order partial derivatives. Our results in special cases yield some of the recent results on Opial's inequality and provide new estimates on inequalities of these types. 2010 Mathematics Subject Classification: 26D15 Full text: PDF