I have a function σ=σ_W+kT/(rS_W )* ln((1-Ka_s)/(1-Ka_s (1-C) ))
here, the value of r , K ,C needs to be sorted out by optimization .
sigma is the surface tension , S_W = 10^-19 , k = 1.38*10^-23 , T=298 K ; a_s= needs to take value from excel file.
my constraints are : 0<K<1 , C>0 and no constraints for r .
i was suggested to use fmincon function to do this ... but i don't have clear idea of this .
Could someone please help ?