Decimal Places in Trendline Equation

Need to increase precision of my power-law trendline equation. Web search brought up instructions: Right-click equation | Format trendline label | Number | Scientific | Decimal Places. Entered a larger number of decimal places, but there is no change to the numbers in the equation.

Same behavior observed on Excel-2007 Win7 and Excel-2011 on my Mac.

Alternative would be to store the equation parameters. How is that done? For linear, there are the SLOPE and INTERCEPT functions. What are the counterparts for a power law: y = A x^B. How can I store A and B?

Any tips appreciated.