i have derived graph in microsoft excel sheet.i want to draw the
tangent line for that graph.but i do not know equation for the graph.
in x and y axis i have some values.i want particular point of xaxis to
draw the tangent line for the graph that would be meet the particular
point of the curve from that point i want to find out corresponding y
value for the graph. please any body know about tangent line for graph
help me.