Assuming that yData and xData are columnar data with no empty or
non-numeric cells, then select 3 contiguous cells in a row and array
enter (Ctrl-Shift-Enter)

=LINEST(yData,xData^{1,3})

As documented by Help, the reculting coeffients will be

(cubic, linear, intercept)

which is the opposite order to what you might expect.

Jerry

Cyanlce wrote:

how do i do cubic regression without the quadratic term? how do i tell excel
there is no x^2? i just want it to be ax^3+bx+c