1. Department of Mathematics, Kohat University of Science & Technology, P.O. Box 26000, Bannu Road, Kohat, Pakistan (Corresponding author), e-mail: zaybasdf@gmail.com, https://orcid.org/0000-0003-2438-5366
2. Department of Mathematics, Kohat University of Science & Technology, P.O. Box 26000, Bannu Road, Kohat, Pakistan
3. Department of Mathematics and Statistics, American University of Sharjah, Sharjah, United Arab Emirates