ENTERING INTERVAL ANSWERS

For intervals of values, enter your answer using interval notation. Here are some examples of how interval notation relates to inequalities:

Inequality	Interval Notation
$\displaystyle {3}\lt{x}\lt{5}$	(3,5)
$\displaystyle {3}\lt{x}\le{5}$	(3,5]
$\displaystyle {x}\gt{3}$	$\displaystyle {\left({3},\infty\right)}$
$\displaystyle {3}\lt{x}\lt{5}\ \text{or}\ {7}\lt{x}\lt{9}$	$\displaystyle {\left({3},{5}\right)}\cup{\left({7},{9}\right)}$

With inequalities, we use "less than": < or "greater than": > to exclude the endpoint of the interval. With interval notation, we use use round parentheses, ( or ).

With inequalities, we use "less than or equal to": ≤ or "greater than or equal to": ≥ to include the endpoint of the interval. With interval notation, we use use square brackets, [ or ].

To combine two intervals, use U (an uppercase letter u) for union: $\displaystyle \cup$
Use oo (two lowercase letter o's) for infinity: $\displaystyle \infty$

For example, to enter $\displaystyle {\left(-\infty,-{2}\right]}\cup{\left({3},{6}\right]}$, you would type: (-oo,-2]U(3,6]

Try it now. Enter the interval equivalent to $\displaystyle {2}\lt{x}\le{5}\ \text{or}\ {x}\gt{7}$