If I have to minimize a function with 2 variables (f(x,lamda))and I have a condition on one of these 2 variables(lamda>=0), how can I find this variable (lamda)? thank u

 minimize(((3.5*log((((1.2* x)+1))/log(2))))-lamda*((((1/(1^2)*x))-10)));
%             subject to 
%            lamda>=0;

Answer 1

[Harshit]

Hi Hiba, You can use an iterative method. Start with lambda. Differentiate your equation with lambda. Change lambda on the basis of sign of derivative until you get zero derivative. Ofcourse it will change with x.

[Harshit]

Sorry you also have to use lagrange multiplier

Answer 2

[Hiba Bawab]

Hi Harshit, thank u , lamda is already a Lagrange multiplier for a first constraint when the others constraints will be included later . for the first step , I should only minimize the function subject to lamda >=0 ; It's a case of dual decomposition method and this is the first step of this method .

I will try iterative method .