Question

The solution to an inequality is given in interval notation as (2, oo). What is another way to represent this solution set?

Answer 1

Assuming the variable is x, we can write $(2, \infty)$ as $x > 2$

The given interval is from 2 onto infinity, basically describing everything larger than 2. We do not include 2 as part of the interval because of the curved parenthesis. If you had $[2, \infty)$ then you would include 2 and you would say $x \ge 2$

In set builder notation, we can write $\{x|x\in \mathbb{R}, \ x > 2\}$ which is basically a more long-winded way of saying $x > 2$. The fancy looking R indicates that x is a real number. So it's saying "we have a set of real numbers such that these numbers are greater than 2".