Problem 85. Remove the polynomials that have positive real elements of their roots.

Created by Cody Team

Solve Later

The characteristic equation for a dynamic system is a polynomial whose roots indicate its behavior. If any of the roots of the polynomial have a positive real part, the behavior of the system will be divergent. Given a cell array of vectors that represent polynomials, remove the ones that have roots with positive real components.
Example:
 polyIn = {[1 1],[1 -1]}
 polyOut = {[1 1]}
since roots([1 -1]) is 1, a positive number.

Solve

Solution Stats

3020 Solutions
1737 Solvers

Last Solution submitted on Dec 16, 2025

Last 200 Solutions

Problem Comments

5 Comments

5 Comments

Show 2 older comments

Cris Luengo on 14 Jul 2012

The test set should contain a polynomial with complex roots where the real part is positive, and a polynomial with a positive and a negative root.

Hans Kramer on 31 Oct 2018

Too less test cases

Brandon on 13 Jun 2023

How does [1 1] represent a polynomial? This problem should read "Remove sets with negative numbers" instead.

Christian Schröder on 14 Jun 2023

@Brandon polynomials in MATLAB are represented by a vector of coefficients; see doc roots.

Aditya Bapat on 5 Mar 2024

interesting problem

Solution Comments

Show comments

Problem Recent Solvers1737

Problem Tags

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Problem 85. Remove the polynomials that have positive real elements of their roots.

Solution Stats

Last 200 Solutions

Problem Comments

Solution Comments

Problem Recent Solvers1737

Suggested Problems

More from this Author96

Problem Tags

Community Treasure Hunt

Problem 85. Remove the polynomials that have positive real elements of their roots.

Solution Stats

Last 200 Solutions

Problem Comments

Solution Comments

Problem Recent Solvers1737

Suggested Problems

More from this Author96

Problem Tags

Community Treasure Hunt

Players