Optimization problem, local minima and feasible set

In summary, the given problem involves minimizing the function f(x) = x_1 with the constraints (x-1)^2+y^2=1 and (x+1)^2+y^2=1. The feasible set, visible on the graph provided, consists of only one point. It is unclear if this point is a local or global minimum, but it is the only obvious choice.
  • #1
retspool
36
0

Homework Statement


minimiza f(x) = x_1
subject to (x-1)^2+y^2=1
(x+1)^2+y^2=1

Graph the feasible set, Are there any local minimizers and global minimizers?

Homework Equations



I have graphed the feasible set
http://www.wolframalpha.com/input/?i=graph+%28x-1%29^2%2By^2%3D1+and+%28x%2B1%29^2%2By^2%3D1


The Attempt at a Solution



I don't know if the local minima is going to be (0,0) cause its common to both the constraints or if its going to be some other pt.

thx
 
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  • #2
what is the function to minimise?
f(x) = x_1

based on the constraints, your feasible set consists of 1 point, so you don't have a whole heap of choices
 
  • #3
Yeah i was confused cause the 2 constraints met at only one pt. Which made it pretty obvious. I was just confirming that it had only one obvious choice, the origin.

Thx
 

1. What is an optimization problem?

An optimization problem is a mathematical problem that involves finding the best solution from all possible options, given a set of constraints. It is often used to maximize or minimize a specific objective function.

2. What is a local minimum?

A local minimum is a point within the feasible set where the objective function has the lowest value compared to all other neighboring points. However, it is not necessarily the overall lowest value for the entire feasible set.

3. What is a feasible set?

A feasible set is the set of all possible solutions that satisfy the given constraints in an optimization problem. It is the region within which the optimal solution can be found.

4. How do you know if you have found the global minimum?

The global minimum is the lowest value of the objective function for the entire feasible set. To determine if you have found the global minimum, you can test different points within the feasible set and compare the objective function values. If the value at a certain point is lower than all other points, it is likely the global minimum. However, in some cases, it may be difficult to determine if the global minimum has been found without testing all possible points.

5. Can a feasible set have multiple local minima?

Yes, a feasible set can have multiple local minima. This means that there are multiple points within the feasible set where the objective function has the lowest value compared to all other neighboring points. However, only one of these local minima can be the global minimum.

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