Significantly different between two nonlinear functions

Is there any way to find out significantly different between two nonlinear functions?

I have these 2 models for the best fit:

y1 = a1/(b1+x) (blue) and y2 = a2/(b2+x) (red)

Mayby I can log the functions and make it linear and check if the e.g angle are > 0?

Answer 1

[Alan Stevens]

Or you could linearise by simply inverting and plotting 1/y1 against x1, and 1/y2 against x2.

[jjohn33]

I need a method to get the significantly difference as well..

[Alan Stevens]

You could calculate the errors on the fits (see linear regression in Matlab's documentation) and compare them.

[jjohn33]

I don't need the error on the fits (I think..) I want to see if the both lines differ from each other

[Alan Stevens]

Find the errors on the slopes and intercepts. Use them to estimate if the lines are the same to within the errors or not.

[jjohn33]

Ok I will try and figure out to get a statistic significance as well