Difference between closed bracket and open bracket?

Question

I'm working on Advanced functions and linear rational funtion. Whats the differnee between a closed and open bracket when stating domain?

Answer 1

closed bracket you can use (equal ) that number as well as it being the boundary number
x > 5 (5, infinity)
x >= 5 [5, infinity)

Infinity always uses an open bracket (parentheses) since it is an "open" number

3 < x < = 8
(3, 8]

if you have an asymptote in a rational function then that number is the edge of interval with an open bracket
ex: if asympote is at x = 2 then domain would be (-inf, 2) U (2, inf)

Answer 2

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An open interval includes the range of numbers in that interval EXCEPT for the end point. A closed interval includes the range of numbers in the interval, INCLUDING the end point. When written as sets of numbers, a parentheses is used to denote an open interval on that end point, and a bracket is used for a closed interval. For example, the solution set to √x <= 10 is [0,100], meaning the set of all real values between 0 and 100, including those two numbers too. But if we had "√x < 10", then x=100 wouldn't work. So the interval here is "[0,100)" which is "open" at 100.

Answer 3

Open versus closed range of numbers. The parenthesis is used to indicate an open end (the number at that end is not included in the range) while a square bracket is used to indicate a closed end (the number at that end is included). For example:

0 0<=x<1 would be written as [0,1)
0 0<=x<=1 would be written as [0,1]

Answer 4

2 < x ≤ 3 is equivalent to
(2,3]

the ( goes with the strict inequality, the ] goes with "or equal."

2 ≤ x < 3 is [2,3)

and of course, if ∞ is involved, that side is always ( or ).