Dynamic Trendline Formula

I have these two formulas to calculate the power trendline of a data set; however, I need them to be dynamic. If there are any blank cells in my data range the formulas error out. Is there any way to get the length of the data set and use only those values.

Here are the two equations:

C: =EXP(INDEX(LINEST(LN(L4:L7),LN(K4:K7),,),1,2))
e: =INDEX(LINEST(LN(L4:L7),LN(K4:K7),,),1)

The problem is that I want to take the data set for the entire column of L and K (example L:L & K:K) and get a power trendline. The data set will only have blank cells at the bottom of the list if that helps and the data will always have data in both K and L that coincides.

Any help would be appreciated.

Thanks,
Kevin

Trendline.xlsx

Pl see file.
Same formuala can be used.Used your information that "data set will only have blank cells at the bottom of the list ". Both the ranges should have equal number of blank cells at bottom only.
Two Dynamic Name ranges Arange & Brange created for A & B columns.

Thanks, that is exactly what I was looking for.