2
votes
1answer
28 views

Formulate the Langrangian function of a non-linear optimization problem and solve it for $y\geq0$

Consider the (non-linear) optimization problem ($P$) $$max \quad3x_1 + 4x_2$$ $$s.t. \quad x_1^2 + x_2^2 \leq 25$$ $$ \quad x_1,x_2 \geq 0$$ Formulate the Lagrangian function ...
1
vote
1answer
67 views

Cost minimization problem

The problem is as follows: A firm uses $k$ units of capital and $l$ units of labor to produce $(k^{\alpha}l^{1-\alpha})^{1/\beta}$ units of output, where $\alpha$ and $\beta$ satisfying $0 < ...
1
vote
0answers
41 views

Formulation of a problem as semidefinite programming

I would appreciate some help with this problem: $R$ is a positive semidefinite matrix $\in{R}^{n\times n}$, $A \in{R}^{n\times m}$. I need to formulate this optimization problem as semidefinite ...
4
votes
1answer
109 views

Kuhn-Tucker condition is not satisfied

Show that the solution to finding minimum of $f(x)=-x_{1}$ With conditions $-\sin(x_{1})+x_{2} \leq 0$ $x_{1}-x_{2} \leq 0$ is point $(0,0)$, but the Kuhn-Tucker condition is not satisfied in this ...
0
votes
0answers
29 views

checking whether or not a function is concave

Given $t$ as a random variable with a smooth distribution $f(t)$ which is independent of $y_{i}$ and a function $f(x)=g(y₁)-αE[max(y₁,y₂)]-βE[max(y₁+t-x,0)]$ with the following properties: ...
1
vote
1answer
133 views

A sufficient condition for a unique maximum of the product of two concave functions

Given two concave functions $f(x)$ and $g(x)$, what conditions in terms of these functions can ensure that $h(x)=f(x)g(x)$ have a unique maximizer on an interval $[a,b]$ for $a<b$?
1
vote
0answers
99 views

sufficient condition for KKT problems

For the Karush-Kuhn Tucker optimsation problem, Wikipedia notes that: "The necessary conditions are sufficient for optimality if the objective function f and the inequality constraints g_j are ...
0
votes
0answers
69 views

Unique utility, but variable Walrasian Equilibrium Consumption set

Basically, I am not sure why the utilities in this economy is unique even though Walrasian Equilibrium consumption is not unique. Here's the setup: Consider an exchange economy with one money good ...
0
votes
0answers
62 views

Iterative scheme for a nonlinear optimization problem

Let $\mathbb{PD}_3 \subset \mathbb{R}^{3 \times 3}$ be the set of the positive-definite $3 \times 3$ real matrices. For given $v \in \mathbb{R}^{3 \times 1}$, consider the function $f_v: ...
0
votes
0answers
40 views

A question in non linear optimization.

If we consider the linearly constrained optimization problem min f(x), A^T.x < b. A is an n X m matrix. The set of feasible solutions is S and for x in S, I(x) is the set of active constraints. ...
1
vote
1answer
87 views

Question regarding Kuhn-Tucker multiplier

I have a problem which I am unable to solve. If we consider the following problem $\min f(x)$, $G(x) = b$; where $f$ is in $C^2(R^n)$, and $G$ from $R^n$ to $R^m$ is a $C^2$-function, $G = ...
0
votes
1answer
322 views

Set of symmetric positive semidefinite matrices is a full dimensional convex cone.

If $S_n^+$ is the set of all symmetric positive semidefinite $n \times n$ matrices with entries in $\mathbb{R}$, how does it follow that it is a full dimensional closed convex cone in ...