SOLUTION: Describe when to use interval notation "∞ " and "-∞"

Algebra ->  Inequalities -> SOLUTION: Describe when to use interval notation "∞ " and "-∞"      Log On


   

Question 1093582: Describe when to use interval notation "∞ " and "-∞"
Answer by Edwin McCravy(20055) About Me  (Show Source):
You can put this solution on YOUR website!
If the number line graph is

<=====================o---------------
-5 -4 -3 -2 -1  0  1  2  3  4  5  6  7

the interval notation is %28matrix%281%2C3%2C-infinity%2C%22%2C%22%2C2%29%29

----------

If the number line graph is

-------------------☻=================>
-5 -4 -3 -2 -1  0  1  2  3  4  5  6  7

the interval notation is %28matrix%281%2C3%2C1%2C%22%2C%22%2Cinfinity%29%29

If the number line graph goes:

1. all the way to the left from point A, including A is (-∞,A]
2. all the way to the left from point A, not including A is (-∞,A)
3. all the way to the right from point A, including A is [A,∞)
4. all the way to the right from point A, not including A is (A,∞)

Edwin