# Get lower bounds and upper bounds of a curve

I have fit the wave data as below using Least Square optimization and used Root Mean square to calculate upper and lower bounds. I wanted to know is there any other alternative exists which gives a higher value for the upper bound and a lower value for the lower bound.

In the below picture, I want upper bound to be above 0.9 or 1 and lower bound to be below 0.2 or 0.3