Supremum and Infima

**Oiler** · March 8th 2011, 10:46 PM

Hi all,

Given a set:
$x \in (-\infty, -2] \cup [-1, \infty)$
would you say that, the least upper bound and greatest lower bound do not exist.
and subsequently for:
$x \in (\frac{-\sqrt{29}}{2}+\frac{3}{2}, \frac{\sqrt{29}}{2}+\frac{3}{2})$ , That the least upper bound is $(\frac{\sqrt{29}}{2}+\frac{3}{2})$ and the lower bound is $(\frac{-\sqrt{29}}{2}+\frac{3}{2})$

**emakarov** · March 9th 2011, 02:03 AM

Originally Posted by Oiler

Given a set:
$x \in (-\infty, -2] \cup [-1, \infty)$
would you say that, the least upper bound and greatest lower bound do not exist.
and subsequently for:
$x \in (\frac{-\sqrt{29}}{2}+\frac{3}{2}, \frac{\sqrt{29}}{2}+\frac{3}{2})$ , That the least upper bound is $(\frac{\sqrt{29}}{2}+\frac{3}{2})$ and the greatest lower bound is $(\frac{-\sqrt{29}}{2}+\frac{3}{2})$

Yes to both questions. When you specify a set, write just $(-\infty, -2] \cup [-1, \infty)$ , not $x \in (-\infty, -2] \cup [-1, \infty)$ .

Nice nickname, Euler.

Thread: Supremum and Infima

LinkBack

Thread Tools

Display

Supremum and Infima

Similar Math Help Forum Discussions

Supremum

supremum

Help finding suprema and infima

Supremum

Supremum example

Search Tags