The results will be very sensitive to how much precision you use for the
coefficients
Ergo: do not use the trendline values but use the results from LINEST
See http://people.stfx.ca/bliengme/ExcelTips/Polynomial.htm
The use formulas that point to the coefficients in the LINEST results to get
the max precision of Excel
best wishes
--
Bernard V Liengme
Microsoft Excel MVP
http://people.stfx.ca/bliengme
remove caps from email

"John1791" wrote in message
...
I am trying to work with trendlines, and I can match my data with a
polynominal trendline. The plotted trendline matches the data points very
closely, but when I apply the formula generated to actual data, my
projected
values are way off. I believe the problem is that the displayed formula
is
rounding constants off and not displaying to the number of significant
figures required to generate a workable formula.

Are there any ways to change any settings to allow Excel to display more
figures in the diplayed trendline formulas?

Thank you in advance.