I have a simple graph, 2 dimensions x and y, y=f(x) but the equation/relation is unknown and I want it !
So I insert a trendline (polynomial level 6 to have the best match). Then I display the trendline equation on the graph.
If I test the equation, applying to the x value the equation, the output is completly out of range.. I tried several times, always wrong output. Either I do not know how to read the equation or it is wrong or incorrectly displayed.
Can I retrieve that equation by any other means such as a bit of code in Visual Basic ?