In Excel 2000 and Excel 2003, I am trying to validate if specific (x,y)
coordinates fall within the area bounded by 4 intersecting curves with
equations "y=f(x)", and am looking for help to set this up. I have tried the
normal logic of IF, AND, OR but have not been successful at all.

Of the four functions of the type "y=f(x)". the fourth one is the CIE 1931
locus of the human eye response to colors, and is a very complex function.
The others are more like "y = mx+c". Since the complex function is
representing the boundary of an instrument's data output, the data will
always be bounded on that side. I am currently more concerned with the first
3 equations of the first order, and would just like to ensure that my data
points are within
their bounds.

Has anyone ever tried this in Excel, or am I the first one to venture into
this area?

--
Mukesh