# Math

posted by on .

Can someone explain to me.... when you are graphing number sets.... when do you use open/ closed cirles.... When do you use arrows?... What are intergers???

Thanks,

ummm kbye<33=]]]]

i don't like mathhh its kinda gayy

can u stop... you are not helping...

BYE!

I'm not exactly sure what your terminology refers to. Do you mean open and closed intervals?
The integers are ...-3,-2,-1,0,1,2,3...
What class is the for?

yes open and closed intergers....

No, I asked if it was open/closed intervals, no integers.
When we specify an open interval we use the parentheses ( and ). We use those when we want to exclude the endpoints, thus (1,2) is the set of points between 1 and 2, but niether 1 or 2.
For closed intervals we use [ and ], brackets. Thus [1,2] is the closed interval and means all point from 1 to 2 inclusive.
We can have half-open/closed or half-closed/open intervals too. Thus (1,2] means all points greater than 1 and less than or equal to 2. [1,2) is all points greater than or equal to 1 and less than 2.