The equation of a parabola has been graphed and the equation displayed using
concatenate. The rate of change has been determined and graphed. To this
graph a trendline is added. The trendline equation is displayed. Then the
parabola is modified and the graph representing the rate of change adjusts.
Unfortunately, the equation of the trendline doesn't change. How can the
display equation of the trendline be displayed dynamicly?

Not sure what you mean by "equation displayed using concatenate"
The coefficients for fitting a polynomial (including parabola) can be placed
in cell with LINEST
See equation displayed using LINEST
See http://people.stfx.ca/bliengme/ExcelTips/Polynomial.htm
best wishes
--
Bernard V Liengme
Microsoft Excel MVP
www.stfx.ca/people/bliengme
remove caps from email

"CJ" wrote in message
...
The equation of a parabola has been graphed and the equation displayed
using
concatenate. The rate of change has been determined and graphed. To this
graph a trendline is added. The trendline equation is displayed. Then the
parabola is modified and the graph representing the rate of change
adjusts.
Unfortunately, the equation of the trendline doesn't change. How can the
display equation of the trendline be displayed dynamicly?