1. Department of Basic Science, The General Administration of Preparatory Year, King Faisal University, Hofuf 31982, Al-Ahsa, Saudi Arabia
2. Department of Mathematics and Statistics, College of Science, King Faisal University, Hofuf 31982, Al-Ahsa, Saudi Arabia
3. Department of Basic Science, Faculty of Engineering, The British University in Egypt, El Sherook City P.O. Box 43, Cairo, Egypt