Finding Max and Min with Lagrange Multipliers: Homework Help

In summary, to find the maximum and minimum of f(x,y)=x^2y with the constraint x^2+y^2=1, you can use the method of Lagrange multipliers and find possible points, which are (\pm\sqrt{2/3}, \pm\sqrt{1/3} for a total of 4 points. It is necessary to check the end points on the constraint, such as (-1, 0), (1, 0), (0, 1), and (0, -1). Also, make sure to change the direction of the slash on the closing tex tag for your latex code to work properly.
  • #1
chesshaha
14
0

Homework Statement



find the max and min of f(x,y)=x^2y, constraint x^2+y^2=1

Homework Equations



None.

The Attempt at a Solution



I found that possible points use the procedure of the method of lagrange multiplier, I got [tex](\pm\sqrt{2/3}, \pm\sqrt{1/3}[/tex] so 4 points total.
But do I have to check the end point on the constraint? like points (-1, 0), (1, 0), (0, 1), (0, -1)?and y this latex thing won't work? help please. lol
 
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  • #2
You should check the boundaries because for 1) they could have max or min depending contexts and 2) they will give you some sanity towards the answer you have.
 
  • #3
Change the direction of the slash on your closing tex tag. [\tex] sould be [ /tex] (witout the space obviously)
 

Related to Finding Max and Min with Lagrange Multipliers: Homework Help

What is the Lagrange Multipliers Problem?

The Lagrange Multipliers Problem is a mathematical optimization problem that involves finding the maximum or minimum value of a multivariate function subject to a set of constraints. It is named after Joseph-Louis Lagrange, who first described the method in the late 18th century.

What are the key steps in solving the Lagrange Multipliers Problem?

The key steps in solving the Lagrange Multipliers Problem are:
1. Formulating the objective function and the constraints
2. Constructing the Lagrangian function by introducing Lagrange multipliers for each constraint
3. Taking the partial derivatives of the Lagrangian function with respect to the variables and the Lagrange multipliers
4. Setting the derivatives equal to 0 and solving for the variables and Lagrange multipliers
5. Checking the solution for optimality by using the second derivative test or the KKT conditions.

What types of problems can be solved using Lagrange Multipliers?

Lagrange Multipliers can be used to solve optimization problems where the objective function and constraints are differentiable. This includes problems in calculus, physics, economics, and engineering.

What is the significance of the Lagrange Multipliers in solving optimization problems?

The Lagrange Multipliers method allows for the optimization of a function subject to constraints, without having to explicitly solve for the constraints. This makes it a powerful tool in solving complex optimization problems that may not have a straightforward solution.

What are some potential drawbacks of using Lagrange Multipliers?

Some potential drawbacks of using Lagrange Multipliers include:
1. The method can become computationally expensive for problems with a large number of variables or constraints
2. It may not always result in a unique solution
3. It may not be applicable to non-differentiable functions or constraints
4. It can be challenging to interpret the Lagrange multipliers in terms of the original problem.

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