National Institute of the Republic of Serbia

Dragoslav S. Mitrinović was born in Smederevo, Serbia, on June 23, 1908. He received elementary and secondary education in Priština and Vranje. In 1932 he graduated mathematics at the Faculty of Philosophy, Univesity of Belgrade: The next year, as a student of Professor Mihailo Petrović Alas, he defended his Ph. D. thesis in the fild of *Differential equations entitled investigations of an important differential equation of the first order*.

Until 1946 D. S. Mitrinović worked as a secondary school teacher. He spent some time as a researcher at the Paris University. During this period Mitrinović published about 50 scientific papers, mainly on differential equations.

Mitrinović started his university career in Skoplje, Macedonia, as an Associate Professor at the Philosophical Faculty. It took him only five years (1946-1951) to found the Skoplje School of Mathematics, including two mathematical journals. His persistent work resulted in the foundation a rich professional mathematical library there and in a wide exchange of scientific publications with foreign countries. Thanks to his scientific contribution he was elected the member of the Macedonian Academy of Science and Art.

From 1951 to his retirement in 1978 Professor Mitrinović taught at the Faculty of Electrical Engineering, University of Belgrade, and in 1953 he was elected the Head of the Department of Mathematics. He founded the wellknown Belgrade School of Functional Equations, Differential Equations and Inequalities. He was also the founder of the *Publications of the Faculty of Electrical Engineering, Series: Mathematics and Physics*, which soon became the worldwide renown journal. Soon after foundation of the first faculties inNiš in 1960, Professor Mitrinović founded another school of mathematics. In the period between 1965 and 1975 he was the Head of the Department of Mathematics at the Faculty of Electronic Engineering, University of Niš.

Professor Mitrinović was a very communicative person. He maintained epistolary relationship with numerous world respectable mathematicians. He was a longtime member of the American Mathematical Society, Societe Mathematique de France and one of the founders of the Serbian Scientific Society. His social activity on the professional plan is also noteworthy. He was the founder of the Mathematical documentation center of the Society of mathematicians and physicists of Serbia, the President of the Society of mathematicians and physicists of Macedonia, the President of the Commission for mathematics of the Federal Council for the coordination of scientific research, etc. For a long time, Mitrinović was a member of the Editorial Board of East European Series *Mathematics and Its Applications*in the Kluwer Academic Publishers.

Mitrinović was a prolific writer of many university books as well as significant monographs of high scientific level, published by the world's most famous publishing houses. His monograph *Analytic Inequalities* (with P. M. Vasić) published in 1970 by Springer Verlag, had a very powerful influence on the development of this field in Yugoslavia and abroad.

The scientific work of Mitrinović and his contributions in mathematics can be classified into the following areas: Differential equations; Functional equations; Inequalities; Complex analysis and special functions. The total bibliography of Professor Mitrinović contains 373 units, including 279 scientific papers and 30 other papers, as well as 17 monographs, 35 text-books, and 12 other books. There are 35 scientists who received their doctoral degrees by Professor Mitrinović.

Beside more than one hundred papers on differential equations and more than thirty papers on functional equations, he published three text-books on differential equations. His starting papers on functional equations from fifties were important for developing a well-known Belgrade School of Functional Equations as well as the appearing of his *Mathematics Problem Book*, Vol. Ill (1960), with several interesting open problems related to the classical functional equations. These problems were a glue" for young mathematicians and for the most talented students.

1 he last and the greatest Mitrinović's passion in mathematics was the one ceiled Inequalities. He was involved in all kinds of inequalities (elementary inequalities; geometric inequalities; means and inequalities; analytic inequalities; inequalities and extremal problems with polynomials; various particular inequalities; inequalities in number theory). He often used to say: *There are no equalities, even in the human life, the inequalities are always met*. His interest in inequalities started very early (1959). To each of the mentioned areas Mitrinović devoted at least one monograph.

Professor Dragoslav S. Mitrinović died on April 2,1995, in Belgrad

His bibliography is found here.

Author: Milovanović, Gradimir V.