# Finding the intersection of two interval notation sets: [1, ∞) & (-∞, 8)

#### chromechris

##### New member
Finding the intersection of two interval notation sets: [1, ∞) & (-∞, 8)

What is the intersection expressed in interval notation of two interval notation sets. The sets are the following: [FONT=&quot][1, ∞) & [/FONT][FONT=&quot](-∞, 8) . My answer is [1,8) . Is this correct? My textbook does not have answers, lol.
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#### Subhotosh Khan

##### Super Moderator
Staff member
What is the intersection expressed in interval notation of two interval notation sets. The sets are the following: [1, ∞) & (-∞, 8) . My answer is [1,8) . Is this correct? My textbook does not have answers, lol.
Looks good to me .....

#### j-astron

##### Junior Member
What is the intersection expressed in interval notation of two interval notation sets. The sets are the following: [1, ∞) & (-∞, 8) . My answer is [1,8) . Is this correct? My textbook does not have answers, lol.
In this case it's not that hard to tell by inspection what the intersection is, but in general, what would you do to check that it's correct? Do you have any ideas?

- do you think it might be useful to draw a real number line and look at the two sets and where they overlap?

- if a number is in the intersection, that means it's in both sets. Could you imagine picking numbers from the intersection and checking to make sure that they are in both sets?

It seems fairly obvious in this case, but you're still asking whether your answer is correct or not. That's why I want you to think about how you'd verify for yourself that it is.