#### themathman

##### New member

- Joined
- Sep 8, 2019

- Messages
- 10

x = [1,2] U[3,4] CR

how would i go about proving this set is not convex

how would i go about proving this set is not convex

- Thread starter themathman
- Start date

- Joined
- Sep 8, 2019

- Messages
- 10

x = [1,2] U[3,4] CR

how would i go about proving this set is not convex

how would i go about proving this set is not convex

- Joined
- Jan 29, 2005

- Messages
- 9,168

Your notation is very poor. Lets see if this is correct.x = [1,2] U[3,4] CR how would i go about proving this set is not convex

\(\displaystyle \mathcal{X}=[1,2]\cup[3,4]\subset\mathbb{R}^1\).

If that is correct, you want to prove that \(\displaystyle \mathcal{X}\) is not convex.

So suppose that \(\displaystyle P\in [1,2] ~\&~Q\in [3,4]\) can you prove that \(\displaystyle (\exists T)[P-T-Q~\&~T\notin\mathcal{X}]\)

Last edited:

- Joined
- Jun 18, 2007

- Messages
- 19,982

Please follow the rules of posting in this forum - enunciated at:x = [1,2] U[3,4] CR

how would i go about proving this set is not convex

https://www.freemathhelp.com/forum/threads/read-before-posting.109846/

Please share your work/thoughts with us - so that we know where to begin to help you. Also include the context - topic being taught in class now.

Please post the EXACT problem as it was presented to you.

To start with: What is/are the property/s of a convex set?

- Joined
- Nov 12, 2017

- Messages
- 5,979

I would start with the definition you were given for a convex set. (This may vary according to what subject you are studying, which is one reason we ask you to state the context and show your work.)x = [1,2] U[3,4] CR

how would i go about proving this set is not convex

So, please state that definition, and tell us how you see it applying to this question.