PlEASE HELP ME!!! I WOULD GREATLY APPRECIATE IT!!!!

Find the least upper bound (if it exists) and the greatest lower
bound (if it exists) for the given set.
Please show all work.

(0, 2)
(−∞, 1)
{x : x2 < 4}
{x : x4 ≤ 16}
{5/2,7/3,9/4}
{0. 9, 0. 99, 0. 999, . . .}
{x : lnx > 0}
{x : x2 + x − 1 < 0}
{x : |x − 1| > 2}
{x : sin x ≥ −1}

What are you having difficulty with on this? Look at the last one.

sinx>=-1

what is the range of sinX? between +1 and -1, right, for any x. So for any x, sinx >=-1. So x is unbounded.

I am uncertain what your difficulty is on this.