The main aim of this book is to present several results related to functions of unitary operators on complex Hilbert spaces obtained, by the author in a sequence of recent research papers.

Silvestru Sever Dragomir is Professor and Chair of Mathematical Inequalities at the College of Engineering & Science, Victoria University, Melbourne, Australia. He is the author of many research papers and several books on Mathematical Inequalities and their Applications. He also chairs the international Research Group in Mathematical Inequalities and Applications (RGMIA). For details, see https://rgmia.org/index.php.

1 Introduction. 2 Ostrowski Type Inequalities. 3 Trapezoid Type Inequalities. 4 Generalized Trapezoid Inequalities. 5 Quasi Grüss Type Inequalities. 6 Grüss Type Inequalities. 7 Inequalities for Bounded Functions.