Dr. Rajesh Singh is an Assistant Professor in the Department of Mathematics, Ramanujan College, University of Delhi. He has a teaching experience of more than 6 years at the University of Delhi. He obtained his doctorate degree in 2019 from the Department of Mathematics, University of Delhi. He has more than 10 Research Publications in journals of international repute and has written several e-chapters on Undergraduate Mathematics for ILLL, University of Delhi. He has delivered invited talks at various international platforms including a lecture in CIMPA Research School held at Lebanese University, Lebanon. His YouTube Channel “COSMOS LEARNING” has more than 300 video lectures that has catered to more than 10000 students of undergraduate mathematics.