Jump to content

Another element that squares to the identity?

Featured Replies

Prove that groups of even order contain at least one element (which is not the identity) that squares to the identity. 

In case of a cyclic group, it is easy. Such group consists of {e, g, g2, g3, ..., gn-1} and contains element h = gn/2. This element, h2 = (gn/2)2 = gn = e.

But how to prove it when the group is not cyclic?

P.S. Oh, got it. Just count the pairs, element and its inverse.

Please sign in to comment

You will be able to leave a comment after signing in

Sign In Now

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.

Configure browser push notifications

Chrome (Android)
  1. Tap the lock icon next to the address bar.
  2. Tap Permissions → Notifications.
  3. Adjust your preference.
Chrome (Desktop)
  1. Click the padlock icon in the address bar.
  2. Select Site settings.
  3. Find Notifications and adjust your preference.