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, and OR, but have not been successful at all.

Of the four functions of the type "y=f(x)". the fourth one is the 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