Multivariable Optimization Problem

In summary, the conversation is about finding a way to represent the number 120 as a sum of three numbers in order to maximize the sum of the products taken two at a time. One method suggested is using Lagrange Multipliers, while the other is using the substitution/partial derivatives=0 and the D=FxxFyy-Fxy^2 second derivative test. The person in the conversation decides to use the second derivative test and explains the steps involved in solving for x, y, and z. Ultimately, the solution is that x, y, and z are all equal to 40.
  • #1
Black Orpheus
23
0
I need to "write the number 120 as a sum of three numbers so that the sum of the products taken two at a time is a maximum." I think this means that x+y+z=120 and xy+xz+yz=maximum. Can someone help me begin this problem?
 
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  • #2
Would you be more confortable using the method of Lagrange Multipliers or using the substitution/partial derivatives=0 and the D=FxxFyy-Fxy^2 second derivative test thinggy?
 
  • #3
definitely using second derivative test thingy
 
  • #4
Got the idea. You set z=120-x-y and plug it into xy+xz+yz, which is then f(x,y). So you take the derivative of that, set the partials equal to 0, solve for x, solve for y, plug those back into z=120-x-y... and you get x, y and z equal 40.
 

What is a multivariable optimization problem?

A multivariable optimization problem is a mathematical problem that involves finding the optimal solution for a function with multiple independent variables. The goal is to find the values of the variables that maximize or minimize the function, while satisfying any given constraints.

What are some real-world applications of multivariable optimization?

Multivariable optimization is used in a variety of fields, such as engineering, economics, and machine learning. It can be used to optimize the design of structures, determine the most efficient production processes, and develop predictive models for complex systems.

What are the common techniques used to solve multivariable optimization problems?

The most commonly used techniques for solving multivariable optimization problems include gradient descent, Newton's method, and the simplex method. These methods involve iteratively updating the values of the variables until an optimal solution is found.

What are the challenges associated with solving multivariable optimization problems?

One of the main challenges of solving multivariable optimization problems is the complexity of the mathematical equations involved. These problems often have a large number of variables and constraints, making it difficult to find an efficient solution. Additionally, the presence of local optima can make it challenging to find the global optimal solution.

How can one determine if a solution to a multivariable optimization problem is optimal?

To determine if a solution to a multivariable optimization problem is optimal, one can use various methods such as sensitivity analysis, checking for convergence of the optimization algorithm, and comparing the solution to theoretical bounds. Additionally, the solution can be tested by changing the values of the variables and checking if the objective function improves or worsens.

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