Hi Syed, <Smart-alec kind of answer to the problem as proposed> Ummm ... with a straight edge, maybe? </saa> Can we have the full wording of the problem? Here is a pretty darn nice explanation/review for how to find lines tangential to curves: http://syllabus.syr.edu/cid/graph/Unit8a.html The 'detailed' solution pretty much fills in the details behind Lach's shorter explanation. Just for fun ... here's a neat animation: http://www.math.umn.edu/itcep/delta-m/tse/TraceTangent.html Here's another explanation: http://www.math.hmc.edu/calculus/tutorials/tangent_line/ HTH, RonL. -----Original Message----- From: Syed Zeeshan Haider [mailto:szh at hotpop.com] I think, I am not proving myself a good student of Maths. Please give me some example for the explanation that you gave. Let I have a point (5,7) on a curve, then how I am supposed to draw a tangent on this point.