# Using excel to determine equation.

i already enter the data, and then obtain the curve graph for the data.
how can i obtain the equation of the curve from excel?

and another question, i have data from day 1 to day 21. how can i get the extimated value for day 30 with excel?
any help will be appreciated.

Integral
Staff Emeritus
You can also extrapolate by selecting your data and "drag fill" the column until you get beyond the x value you need. For this to work you need a constant $\Delta$x in your data.