There are twenty (20) problems here that you can use to practice your skill in writing interval notations. Part 1. Write each inequality as an interval notation. 1) x < 3 Answer \left( { - \infty ,3} \right) 2) x \ge - 7 Answer \left[ { - 7,\infty } \right) 3) - 1 < x \le 5 Answer \left( { - 1,5} \right] 4) x < 0 Answer \left( { - \infty ,0} \right) 5) 2 \le x \le 6 Answer \left[ {2,6} \right] 6) x \ge 1 Answer \left[ {1,\infty } \right) 7) - 10 < x < 0 Answer \left( { - 10,0} \right) 8) \large{x > {1 \over 2}} Answer \left( {{1 \over 2},\infty } \right) 9) \left| x \right| < 4 Answer \left( { - 4,4} \right) 10) x \ne 0 Answer \left( { - \infty ,0} \right) \cup \left( {0,\infty } \right) Part 2. Express each phrase as an interval notation. 1) all real numbers greater than 17 Answer \left( {17,\infty } \right) 2) all real numbers less than or equal to -2 Answer \left( { - \infty , - 2} \right] 3) all real numbers between -3 and 2, including -3 but not including 2 Answer \left[ { - 3,2} \right) 4) all real numbers greater than 0 Answer \left( {0,\infty } \right) 5) all real numbers greater than or equal to 13 Answer \left[ {13,\infty } \right) 6) all real numbers between -1 and 1, including -1 and 1 Answer \left[ { - 1,1} \right] 7) all real numbers less than 5 Answer \left( { - \infty ,5} \right) 8) all real numbers between 0 and 100, not including 0 but including 100 Answer \left( {0,100} \right] 9) all real numbers that are less than 3 units from 0 Answer \left( { - 3,3} \right) 10) all real numbers not equal to -1 Answer \left( { - \infty , - 1} \right) \cup \left( { - 1,\infty } \right) You might also be interested in: Interval Notation |