Modifying trendline so that is <= all points on a plot (more of a "lowest limit")

[rark]

Hello,

I have a plot where I want to calculate the "lower limit" of all points. (See the red line in the attached image I would like to calculate)
The trendline function easily gives me an power-function through the the plot, could I perhaps adjust this so that all points is equal or larger to the trendline?

Best regards,