G Shanker Rao, formerly the head of the  department of mathematics at Government Giriraj PG College, Nizamabad, is  presently a faculty member in the department of mathematics at the University  College of Engineering, Osmania University, Hyderabad.  He has nearly 37 years of experience in teaching numerical analysis, real  analysis, graph theory, and statistics to undergraduate and postgraduate  students. A prolific writer, he has authored more than 25 books and several  research papers.