Hari Kishan is Senior Reader in Mathematics at Kishori Raman Postgraduate College, Mathura, affiliated to Dr. Bhim Rao Ambedkar University, Agra. He has 34 years of teaching experience of degree classes to his credit. He completed his M.Sc. from B.S.A. College, Mathura in 1971 and obtained a record percentage of marks for which he was awarded Gold Medal by Agra University. He received Ph.D. degree in Mathematics (Fluid Dynamics) in 1981 from the same university. His topic of research was ‘Flow of Homogeneous or Stratified Viscous Fluids.’ He has got published numerous research papers in several mathematical journals of repute. Besides, he is a well-known author of a large number of books on Mathematics, including Coordinate Geometry of Two Dimensions, A Textbook of Vector Algebra and Vector Calculus, Sure Success in Convergence, Differential Calculus, Integral Calculus, Integral Equations, Coordinate Geometry of Three Dimensions, Matrices, Modern Algebra, Theory of Equations, Dynamics, Statics, Hydro Statics, Real Analysis and Numerical Analysis.