When you find the interval of an inequality, you might be asked to show the answer on a number line. If there are more than one inequality, you’ll have to show where all of them are true. This is how you do it:
Rule
Example 1
Solve the inequality and draw the interval
Draw the sign charts for the solution and read the interval off the sign chart.
You can see that the inequality is true in the interval .
Example 2
Find the intervals where the expressions and are both true
Begin by setting up and solving the inequalities:
Then you can draw the sign charts for the inequalities and read off where they’re both true.
You can see that both of the inequalities are true on the interval .